SPECIES FOUNDATION RHODODENDRONS
Short description of most species.
updated from RSF catalogs by Jerry L. Fickes
updated by Hans Eiberg 1997-2002
Go to species: r s t u w v x y z
Deciduous shrubs or small trees. In cultivation this species generally
forms a slow-growing, well-branched small shrub with an upright habit.
The leaves are arranged in whorls of five at the ends of the branches
and usually have a red margin early in the season. The delicate white,
funnel-shaped flowers have green spots and hang singly or in groups of
two or three, emerging with the soft new green foliage in mid-spring.
A choice and highly sought after species rarely offered although it is
quite common in some areas of Japan where it is native to forests from
1,000 to 5,575 ft. from N Honshu to Shikoku.
225sd97 RSBG ((10\R2\2-3). Beautiful seedlings from the AM form
'Five Arrows' (73/234).
314sd1999 YK#1291:RSBG ('10\R2\2-3). These are seedlings grown
from seed collected wild at 4,850 ft. on the island of Honshu,
Japan. Our first offering of this choice species from wild-
source material. A very exciting opportunity. I truly hate to
have to sell any of these.
IJ-027 Seedling of [73/234 ('Five Arrows') EXB (-5)].
138sd2000 RSBG (-10\R2\2). Extremely ornamental deciduous azalea
with leaves in whorls at the branch tips. White funnel-shaped
flowers with green spots in mid-spring. Red fall foliage color.
These are grown from seed collected from plants here in the RSBG.
Best in light shade. Resents disturbance once established.
Upright-growing to rounded, small-leaved evergreen shrubs with white
to pale or deep pink flowers in mid-spring. The flowers are borne in
the axils of the upper leaves which gives one the impression of a long
'pink or white raceme. The attractive foliage is often blue-green on
the upper surface with a glaucous white coating on the lower. A common,
widespread and variable species in the wild. The many forms in
cultivation are quite variable in height and hardiness but all are
generally heat and drought resistant. An easy and floriferous species.
Found in a wide variety of habitats from 2,500 to 14,000 ft.in China
(N Yunnan, SW Sichuan; W Guizhou).
77/677 CRA (-5). A compact form collected by Reginald J.
79/009 R 11403 (USDA 59717): PS (-5). Light pink flowers
along red stems on this upright selection.
79/180 'Rock Rose' R#11265:Nymans ('5\R1\3). Red-purple
flowers on this famous and floriferous Award of Merit clone (1970).
374sd96 SEH#025:RSBG ((5?\R1\3). Grown from seed collected
wild at 9,800 ft. in SW Sichuan, China.
391sd1996 SEH#042:RSBG ('5\R1\3). My own collection from 11,150 ft.
in SW Sichuan Province, China.
508sd96 SEH#179:RSBG ((5?\R1\3). Grown from seed collected
wild at 9,800 ft. in NE Yunnan, China.
Large erect evergreen shrubs or small trees with pale brown bark.
The upper surface of the broadly lanceolate leaves is a dark glossy
green, the lower is smoothish. The tubular bell-shaped flowers
(mid-spring) are rich rose, crimson, purplish or blood red with
darker nectar pouches and form a tight round inflorescence.
A rare species in cultivation with early growth a problem in
colder climates. Native only to SE Tibet where it occurs in
forests from 8,000 to 10,000 ft.
70/164 GLN (+10?\R1\5). I have not seen this clone in bloom.
Rarely offered collector's species.
LAM (+10). Form with deep rose flowers.
Epiphytic slender shrubs to 4 ft. Flowers (April-November) are
deep pink, crimson to scarlet or blood red. Common over local
area. Found on tree trunks or rotten stumps in mountain forest,
also in light/ moss-forest at 5,200 to 11,000 ft.
85/001 EWS (+32). Form with deep rose-pink flowers.
Compact rounded evergreen shrubs with bristly branchlets and petioles.
The flowers (early to mid-spring) are white flushed pink, pink, or
rose, with crimson spots. The glossy dark green leaves have a
distinctive thick indumentum on the underside, yellow-brown to
cinnamon in color. A highly prized, slow growing species with
superb foliage requiring excellent drainage and some protection
from the sun. Known only from one Kingdon Ward collection in
N Burma where it was found on steep slopes of scree and among
boulders at 11,000 ft.
74/098 KW 7184: GRE: UBC (-10). Form with bold pink flowers
in early April and dark yellow indumentum.
74/099 HIL (-10). Form with rose-pink flowers and mustard-
75/056 KW 7184: NYM (-10). Form with shorter leaves and less
dense indumentum than typical, but a denser shrub with large
pink to white flowers.
This is a complex of large deciduous azaleas closely related to
each other and perhaps best treated as one species. They form
beautifully shaped plants with attractive flowers (mid-spring to
early summer) in shades of lavender, rose, purple and white. The
unusual but striking foliage often provides a bright display of
color in the autumn. An underused but highly desirable group of
species performing well even in warmer climates. Native to Japan
in a wide variety of habitats and elevations.
284sd1995 95ARS#468:RSBG ('10'\R1\4). These are large seedlings
grown from seed collected wild in Japan as wadanum.
249sd96 YK#1059:RSBG ((10?\R1\4). Grown from seed collected
wild at 1,200 ft. in Yamaguchi Prefecture, Honshu, Japan.
260sd96 YK#1017:RSBG ((10?\R1\4). Grown from seed collected
wild at 1,350 ft. on Mt. Shiradake, Tsushima Island, Nagasaki
Prefecture, Kyushu, Japan.
Tropical evergreen shrubs or small trees with small obovate to
elliptic leaves in pseudowhorls. The cylindrical to narrowly
funnel-shaped flowers are red. A long and heavy blooming
attractive species. Native to Indonesia (Java & Sumatra) where
it occurs from 4,300 to 11,100 ft.
79/027 EWS (+32\R2\?)/ Form with five pure red funnel-shaped
flowers per truss.
rex ssp. arizelum
Large shrubs or small trees, 10 to 25 ft. Flowers (March-April)
are cream to yellow, flushed rose, apricot, deep rose with
crimson basal blotch. Leaves with thick rust to cinnamon or fawn
colored indumentum. Native to open conifer forests and thickets
from 10,000 to 14,000 ft. China, NE Burma
65/335 (arizelum 'Brodick') BRO (+10). Compact trusses of
purple-pink flowers with a contrasting dark red blotch. An
Award of Merit form, 1963.
82/031 (arixelum) Forrest 21861: WER-UBC (+15).
rex ssp. fictolacteum
Large shrubs or small trees to 40 ft. under ideal conditions.
Flowers (April) are white through blush-pink, pale lilac to rose,
often heavily spotted and blotched. Large glossy green indumented
leaves. One of the best larger species suitable for cooler areas.
Native to conifer forests and thickets from 10,000 to 14,000 ft.
China, NE Burma
75/158 (syn. fictolacteum) R 84: FR (-5). Hardy form with
rex ssp. rex
Large erect evergreen shrubs or trees which can attain heights of up
to 45 ft. in the wild. The extremely attractive leaves are up to 18
inches long, deep green above with a thick gray to buff indumentum
beneath. Many (up to 30) flowers in a large inflorescence in various
colors, ranging from white to pale lilac, pale pink and mauve-pink,
with a crimson blotch and spots. A beautiful and impressive species
blooming in mid- to late spring. In my opinion, one of the finest
species in the genus with great foliage, beautiful flowers and very
good hardiness for a 'big-leaf'. Common from 10,000 to 14,000(') ft.
in SW Sichuan and N Yunnan, China where it often forms pure forests.
75/118 R.18234(03800) - Windsor (0). An Award of Merit form,
76/181 RBG (-5)
364sd1996 SEH#014:RSBG ('5\R1\5). Grown from my collection of
seed at10,650 ft. in S Sichuan, China. Plants from this
collection have a white indumentum covering the new growth
134sd2000 rex ssp. rex RSBG (-5\R1\5). In my opinion, the best
all-around big-leaf for the typical gardener on the west coast of
North America. Large attractive leaves up to 18 inches long with a
thick gray to buff indumentum beneath. Large flowers of white to pale
pink or mauve-pink with a crimson blotch or spots. These seedlings
are grown from a controlled-cross between 1976/181 (RBG Edinburgh) x
1975/118 (the AM form 'Quartz' from R#18234).
Upright growing evergreen shrubs. The leaves are usually blue-
green with gold or brown scales on the lower surface. The widely
funnel-shaped flowers (mid-spring) are white to lilac-rose or
rose-lavender, usually with gold to brownish spots. A floriferous
and easily grown species tolerant of full sun or woodland conditions.
Native to N Yunnan & S Sichuan, China where it occurs in a wide
variety of habitats from 2,500 to 11,000 ft.
69/742 JAM:WOOD (0\R1\5). Pure white flowers with magenta-brown
spots on the upper lobes.
HI073 Seedlings ( grown from seed collected in Yunnan and sent to
us by the Nanjing Botanical Garden.
Wide-spreading to upright semi-evergreen shrubs. The leaves of
this "evergreen azalea" are covered with reddish hairs. The
widely funnel-shaped flowers (mid- to late spring) are white to
rose or pink. An attractive, free-blooming and heat tolerant
species. A native of S Japan where it occurs along riverbanks.
98/734 USNA#45459 (+5\R1\2-3). Large bright lavender flowers
with a slight fragrance.
Large, very upright-growing evergreen shrubs or small trees
blooming in late winter or early spring. The distinctly-colored
bell-shaped flowers are purplish to violet or blue-mauve with
showy dark nectar pouches. The lower surface of the leaves is
covered with a thin white plastered indumentum. Native to
forests and open rocky slopes from 4,000 to 7,200 ft. in a
limited area of SC Sichuan, China.
65/454 LEO (+5\R1\6). Light purple buds (74B) opening to pale
lavender flowers (76C).
75/013 HIL (0). Form with soft purple flowers.
84/022 (+10). Lavender flowers.
(possible hybrid of R. neriiflorum)
included for historical interest.
74/025 Caerhays - FR (0). Plant originating at Caerhays with
bright red flowers, plant habit and leaf shape of R.
neriiflorum, but a striking purplish-red underleaf rather than
glaucous. Selfed seed has reproduces this character.
Large evergreen shrubs or small trees. The foliage of this hardy
big-leaf species is quite distinct with the large oblanceolate to
obovate leaves tapering to a very short and winged petiole. The
indumentum on the lower surface is thin, brownish and distinctly
'granular' in appearance. The flower color is remarkably variable,
ranging from white to pale yellow or pink, sometimes with a blotch.
An interesting, rare and hardy species which probably represents
a stabilized hybrid swarm between praestans and arizelum (i.e. it
has 'speciated out'). This is another big-leaf that is rarely labeled
correctly in gardens - they are almost always garden-origin hybrids.
Found only in the Tapao (or Dapao) Shan of W Yunnan, China where it
occurs in mixed forest from 11,000(') to 13,000 ft.
75/182 Rock 157:CS (+5)
224sd1997 RSBG (0\R1\4). These are large vigorous seedlings
grown from controlled-pollinated seed produced here in the
RSBG using 1975/18' (R#157) selfed. Very attractive foliage.
The real thing.
roxieanum var. cuculatum
261sd1997 roxieanum var. cucullatum AC#1968:RSBG (-15\R2\3). Choice
and slow-growing rounded shrubs with superb foliage. The leaves are
almost sessile on the stems and are deep glossy green above with a
deep red-brown indumentum beneath. White flowers in mid-spring,
often with red flecks. Best in light shade and well-drained soil.
The "wide-leafed" roxieanum. Grown from seed collected wild in
304sd1997 roxieanum var. cucullatum JN#344:RSBG (-15\R2\3). As above
but from seed collected wild by Jens Nielsen at 12,960 ft. at 99
Dragon Pool, NW Yunnan, China. One of the finest foliage plants in
the genus. Plants of this taxon in cultivation are often labeled
roxieanum var. oreonastes
Upright and compact evergreen shrubs or small trees (when very, very
old). One of the finest foliage plants in the genus with long linear
leaves less than one inch wide. Quite distinct and almost coniferous
in appearance. The leaves are dark and shiny green above with a thick
and woolly brownish indumentum beneath. The flowers (mid-spring) are
borne in a tight round inflorescence. They are white to cream in color
often with a pink flush and reddish spots. This variety is tolerant
of much more direct sunlight than its wider-leafed relatives. Native
from the Tibet/Yunnan frontier into NW Yunnan and SW Sichuan, China
from 11,000 to 14,000 ft. in a wide variety of montane habitats.
74/117 Hilliers ('5\R2\3). White flowers with pale magenta flecks.
74/128 R#:Windsor ('5\R2\3). White flowers with a few magenta spots.
92/101 (roxieanum var. oreonastes) BERG (0). Narrow leaf form.
roxieanum var. roxieanum
An extremely variable evergreen shrub or small tree. The leaves
range in shape from almost linear in var. oreonastes to oblong or
oblanceolate and up to 1.5 inches wide in var. cucullatum. The
very attractive foliage has a deep red-brown indumentum on the
lower surface. The flowers (mid-spring) are white or cream, often
flushed with rose and spotted red. Native over a wide range of NW
Yunnan, SW Sichuan and adjacent SE Tibet where it occurs in various
montane habitats from 11,000 to 14,000 ft.
74/116 GRE - UBC (0). A non-narrow leaf form with flowers
white to pale yellow and crimson flecks.
74/117 Hillier - PHB (0). A narrow leaved form of
R. roxieanum with an upright habit.
78/122 R#138:Smith,C. ('5\R2\3). This form is intermediate
between the narrow and wide-leafed varieties. Attractive,
long and lanceolate, deep olive-green leaves.
92/098 BRA:BERG (0). Wide leaf form.
312sd1997 roxieanum var. roxieanum JN#267:RSBG (-15\R2\3). This is
the "typical" form of this variable species, with leaves intermediate
in width between the wide var. cucullatum and the very narrow var.
oreonastes. Grown from seed collected wild by Jens Nielsen at
13,600 ft. on the Beima Shan, NW Yunnan, China.
Shrubs or small trees to 30 ft. Flowers (March-April) are pink to
mauve, lavender, or rarely white and with purple, or brown to
crimson flecks. Attractive and vigorous ornamental plants for the
garden. Dark brown or rust-colored scales on the leaf
undersurface. Widely distributed and variable with some less
hardy forms. Grows in oak, spruce, and pine forests, among
thickets, and on open slopes at 8,000 to 11,500 ft. China.
66/627 YU 14990: WGP (0). Rose-lilac flowers.
71/413 (syn. desquamatum) BH (+10). Lavender-mauve flowers.
73/130 FR: PHB (-10). Form with bright lavender flowers.
77/688 (syn. desquamatum) BRO (+10)
79/185 (syn. desquamatum) ACU Berry (+10)
80/151 Heritage Plantation, MA (0)
82/162 (syn. desquamatum) JCB (+10).
83/015 (syn. desquamatum) PC: WEB (+10)
83/223 ADB (-10). Form with white flowers.
Upright to spreading evergreen shrubs with branchlets and
foliage covered by a dense layer of appressed hairs. The
flowers (late spring to early summer) are funnel-shaped and
pink to lavender in color, usually with spots. A floriferous
and fairly hardy evergreen azalea with attractive foliage
and flowers which should be quite heat tolerant. Native to
C Taiwan where it occurs on sunny hillsides from 6,500 to 10,500 ft.
73/241 USDA#325046 (+5\R1\3). Rose-pink flowers with darker
flecks on this rarely offered species.
73/242 USDA#325049 (+5\R1\3). Red-purple flowers with darker
flecks on this rarely offered species.
Compact and rounded evergreen shrubs. The narrowly obovate to
elliptic leaves are similar to those of the well-known R. bureavii
but with a typically thinner red-brown indumentum on the lower surface.
The flowers (mid-spring) are white to deep pink, often with reddish
spots. A very hardy species that is seldom seen in cultivation. Native
to S Gansu and N Sichuan, China where it occurs in various habitats
from 8,000 to 13,000 ft.
74/040 R#13649:Windsor ('15\R1\4). Our first offering (2002)
of this species in many, many years. Best in light shade.
Shrubs or small trees up to 15 ft. Flowers (flowering time
varies) are pink to crimson, deep magenta, bright purple or
blood-red. Flowers can be scented. Found in mossy forests to open
exposed ridges from 6,000 to 10,000 ft. North Borneo.
79/024 D. Stanton - EWS (+32)
rupicola var. chryseum
Dwarf and compact evergreen shrubs with tiny fragrant leaves. The
lower surface of the leaves and the young stems are densely covered
with mixed dark brown and tan scales. The flowers (mid-spring) are
dark to pale yellow. A choice and rare (in cultivation) alpine species
providing a nice color change from the purple shades so predominant
in this subsection. Best in a cool but bright site with excellent
drainage. Native to NE Upper Burma and China (SE Tibet, NW Yunnan
; SW Sichuan(')) where it occurs in various alpine habitats from
11,000 to 15,500 ft.
75/028 FR (-10). Form with clear yellow flowers.
320sd1993 TS#9248:RSBG ('10\R3\2). Grown from seed collected
wild in SE Tibet, China by June Sinclair.
93sd353 SB#9292:RSBG ((10?\R3\2). Grown from seed collected
wild in SW Sichuan.
rupicola var. rupicola
Dwarf shrubs to 2 ft. Flowers (April-May) are purple, deep plum
to almost black purple, occasionally deep crimson, or more rarely
white. Noted for the often very dark purple-colored corollas.
This species named after its native habitat as a dweller in stony
places. Common and widespread on rocky slopes of mountainsides
from 10,000 to 15,000 ft. N Burma, China
65/458 WIS (-5). Violet-purple flowers.
Dwarf alpine evergreen shrubs with small, scaly, elliptic to rounded
leaves. The small, broadly funnel-shaped flowers are indigo-blue to
reddish purple or pink-lavender. An outstanding and easily grown rock
garden or specimen plant with beautifully-colored flowers. Very
floriferous and best in full sun with good drainage. The blue-purple
flowers are among the best in that color range in the genus. Native to
NW Yunnan ; SW Sichuan, China where it occurs in various alpine habitats
from 11,000 to 14,000 ft.
66/602 CAE (-10). Deep green leaves speckled with dark
scales and bright indigo-purple flowers.
70/367 KEW (-10). Form with deep purple flowers.
73/244 FR (-10). Bright purple flowers.
77/412 russatum Mulligan (-10\R1\3). Compact rounded shrub with small
scaly leaves and masses of bright blue-purple flowers in mid-spring.
Best in full sun with good drainage. Our best "blue" russatum
79/116 F 25500: BH (-10). Purple flowers.
80/052 Borde Hill 1st RHS (-10)
82/202 'Black Violet' WEB (-10). Dark violet flowers. A very floriferous species.
saluenense ssp. chameunum
Compact prostrate or dwarf mounding evergreen shrubs with
attractive tiny rounded leaves. These are shiny and smooth
on the upper surface with a dense layer of brownish scales
beneath and bristly margins. The widely funnel-shaped flowers
mid-spring to early summer) are purple to reddish purple or
magenta. A choice dwarf species for the rock garden or a
colorful mass planting as a large-scale groundcover. Native
to alpine habitats from 11,500 to 17,000 ft. in NE Burma and
China (SE Tibet, NW Yunnan & SW Sichuan).
73/246 (chameunum) EXB: WW: PHB (-5). An award form with
bright purple flowers in late April.
80/076 (chameunum) CH (-5). Purple-rose flowers.
93sd309 TB#9210:RSBG ((5\R1\2). Grown from seed collected wild
in SE Tibet.
saluenense ssp. saluenense
Erect but compact evergreen shrubs with bristly leaves and stems.
The widely funnel-shaped flowers (mid-spring) are magenta to purple
or red-purple. An excellent alpine species for the rock garden,
tolerant of sun but requiring excellent drainage. A bit more vigorous
and larger than the closely related and more widely grown ssp. chameunum.
Native to SE Tibet, NE Burma and NW Yunnan, China where it occurs from
11,000 to 14,000 ft. in various alpine habitats.
69/876 R#110:Wood ('5\R1\3). Deep rose-purple flowers with
dark red-purple flecks.
75/257 ACB (0)
82/163 Hu Yu: JCB (-5). Form with light purple flowers.
Broadly upright deciduous shrubs. The rhombic (diamond-shaped) leaves
of this distinct species are a deep glossy green and arranged in whorls
at the branch tips. The flowers (late spring to early summer) are deep
rose to rose-purple in groups of three to four. A lovely and unusual
azalea considered rare in its native Japan where it grows in the
mountains of S Honshu. A widely adaptable, heat and cold tolerant
species, best in light shade or the woodland garden.
73/250 GIG (0). Lavender-rose flowers.
76/080 MB (0)
150sd1998 RSBG ('10\R1\4). These are seedlings from a 'superior
form' grown in the east coast garden of Dr. Nickolas Nickou. Choice.
sanguineum ssp. didymum
As above but with deep blood-red or black-crimson flowers in early to
mid-summer. Said to prefer an almost alkaline soil but we have had little
difficulty here at the RSBG. The leaves and branchlets are often more
bristly than ssp. sanguineum. Found in SE Tibet and adjacent NW Yunnan,
China from 14,000 to 15,000 ft. in rocky meadows and on limestone cliffs.
68/215 R 44: CHP (0). Black-crimson flowers.
78/071 Crarae ('5\R3\3). Deep red flowers
sanguineum ssp. sanguineum
Compact rounded evergreen shrubs. The leaves are smooth and often
shiny above with a thin silver to gray indumentum below. The fleshy
bell-shaped flowers (mid- to late spring) are extremely variable in
color, ranging from deep blackish crimson to crimson, pink, yellow or
white. An extremely variable species with numerous subspecific taxa.
Requires a well-drained and partially shaded to fairly exposed position.
Native to China (SE Tibet and NW Yunnan) from 10,000 to 14,500 ft. in
various well-drained montane habitats
70/135 (var. didymoides) Stronachullin ('5\R2\4). This variety is
distinguished by its glandular ovary and usually persistent bud
scales. I have not recorded flowering data on this clone.
88/064 R#6A:ROBB ((5\R2\4). This was collected as R. sanguineum
aff. but lies well within the parameters of the description
for R. sanguineum. Deep blood-red flowers with black overtones
and a large calyx of similar coloration on this clone.
sanguineum ssp. sanguineum var. cloiophorum
Dwarf shrubs, 1 to 4 ft. Flowers (April-May) are white to pink or
yellowish-pink. Found among scrub and on open stony slopes at
10,000 to 14,500 ft. China
77/753 (sanguineum ssp. cloiophorum) F 25521 (=25943): WGP (0)
sanguineum ssp. sanguineum var. haemaleum
Dwarf shrubs, 1 to 4 ft. Flowers (May-June) are very dark
crimson, almost black. Can be semi-deciduous. Found in open scrub
and rocky forest margins from 10,000 to 14,000 ft. China
65/403 (sangueneum ssp. haemaleum) CRA (-5). Form with
crimson flowers in late April.
80/123 (sanguineum ssp. haemaleum) HER (-5)
84/153 H.L. Larson (0)
A rare vireya species from mainland Asia where it occurs in the
temperate rainforests of NE India. This charming
dwarf has small elliptic leaves and short bell-shaped white flowers.
Not particularly “flashy” but a favorite of all who grow it and a reliable
Densely-branched, dwarf evergreen shrubs with small and scaly,
fragrant leaves. The small daphne-like flowers (mid- to late
spring) are pale yellow to cream in clusters of 5 to 12. A choice,
floriferous dwarf species for the rock garden or other sunny locations.
Requires excellent drainage and is relatively slow-growing and
difficult to propagate. Native only to central Sichuan where it occurs
from 10,000 to 14,000 ft, on cliffs and rocks. Has not been collected
in the wild since 1904! (I guess some of us had better get busy.)
1974/104 'Whitebait' Glendoick ('5\R2\2). This AM clone with
creamy white flowers in mid-spring is a more upright and vigorous,
easier grown plant than most forms in cultivation
saxicolum affinity DJHMV#043
An evergreen azalea with small elliptic and hairy leaves. The flowers
are white flushed rose. From seed collected in the wild. Many of the
species collected in this same region are proving to be hardier than
their provenance would suggest. Should have heat tolerance as well.
The beautiful foliage is strongly flushed red when young. (+5?\R1\3)
Shrubs to 20 ft. Flowers (flowering time varies) are pale to dark
red long tubes. Very dark scales cover leaves and flowers.
Epiphytic or more rarely, terrestrial in tropical rain forests
from 6,400 to 8,800 ft. Papua New Guinea
86/022 UCB 62-201-UCB (+32)
scabrifolium var. scabrifolium
Shrubs to 10 ft. Flowers (April) are white to deep pink. Unusual
bullate leaves. Native to dry hillsides and rocky slopes at 6,000
to 9,500 ft. China
70/155 BRO (0). Form with light pink flowers.
scabrifolium var. spiciferum
Shrubs to 6 ft. Flowers (April) are rose to pink or white. Leaves
with soft hairs. Native to dry rocky slopes, pine woods, thickets
and scrub at 8,000 ft. China.
64/106 (syn. spiciferum). BRO (+5). Rose-pink flowers.
80/161 (syn. spiciferum) PM (-5). Form with light pink
Rounded deciduous shrubs often as wide as high. The distinctive obovate
foliage is arranged in whorls of five on the ends of the branches. The
almost flat-faced flowers (early to mid-spring) are pink to rose or white,
with a slight fragrance and reddish spots. The Royal Azalea is one of the
most beautiful of species and an excellent choice for the woodland or partly
shaded garden. Quite hardy and easy with excellent fall foliage color.
Native to Korea and NE Manchuria where it is a common species in woodlands.
80/163 ESC: VVN: KWG (-25). Pink flowers.
90/SD2 Seedling KOR.
90/SD3 Seedling KOR.
177sd1998 HC#970380:RSBG ('25\R1\4). Grown from seed collected in the
wild at around 4,500 ft. on Chiri san in Korea.
Upright evergreen shrubs with stiff and shiny leaves. A free-blooming
species with large, usually fragrant, funnel-shaped flowers. These
are white or white flushed pink with a yellow blotch and frilled
lobes. A rare maddenia in cultivation requiring excellent drainage.
Known in the wild only from SE Tibet where it occurs on rocks and
cliffs from 6,000 to 8,000 ft.
80/135 Trengwainton (+32)
98/014 scopulorum KW#6354:Glendoick (+15\R2\5). Rare maddenia with
large funnel-shaped white flowers with a yellow blotch. Known only
from the Tsangpo gorge region of Tibet. Excellent drainage required
233sd1998 AC#3669:RSBG (+15\R2\5). These are cutting-grown
plants from our original seedlings grown from seed collected
wild by Alan Clark near Bayi in SE Tibet.
Shrubs to 13 ft. Flowers pale outside, dark rose inside,
sometimes white. Carnation scented. Found at 7,000 ft. New Guinea
80/148 BOS (+32)
Vigorous upright evergreen shrubs. The leaves have three sizes of scales
on their lower surfaces. The widely funnel-shaped flowers are white to
rose-purple in mid-spring, typically with spots. A floriferous, easily
grown, and relatively hardy species which is rarely seen in gardens.
Tolerant of sun or partial shade. Known only from W Sichuan, China where
it occurs on the famous holy mountain of Wa Shan in woodlands from 7,500
to 10,000 ft.
70/125 Glendoick ('10'\R1\5). Red-purple flowers with darker spots
Shrubs, 8 to 15 ft. Flowers (April-May) are white or pale purple
with green spots. Known only from two collections from thickets
and woods at 7,500 to 10,000 ft. China
Our first offering of this rare species which forms a dwarf evergreen
shrub with remarkable foliage and extremely unusual flowers. The new
growth, stems and small, heavily bullate ovate leaves are covered with
a thick coating of red-brown indumentum. The whole plant is remarkable
furry and indeed, at the bottom of each flower, the ovary itself is
covered with a prominent tuft of long red-brown hairs. The flowers,
though relatively small, are quite large in scale with the rest of the
plant. They are deep yellow and like a flattened bell in shape. Very
interesting growth habit as well. As seen in the wild, most plants
were either prostrate on the sides of boulders or grew with long hanging
stems from the crotches of trees. Until we found this species in
1997 along the NW Yunnan/Burma border, it was known in cultivation
from only one clone (KW#9254 - collected in 1931) grown and distributed
by Glendoick Nurseries of Scotland. This new collection has a much
thicker and deeper colored indumentum and bigger, deeper yellow
flowers than the old clone. Not the easiest thing to grow but fine
if provided with excellent drainage (use vireya or orchid mix for
example). Native to NW Yunnan, SE Tibet and N Burma where it occurs
as an epiphyte or on cliffs and rocks from 6,000 to 10,000 ft.
387sd1998 CCHH#8106:RSBG (+10'\R2\3). Grown from my collection of
seed at 6,650 ft. on the Salween\Irrawaddy divide. Stunning
foliage and fuzzy white new growth on these seedlings. A choice
collector's plant, closely related to R. edgeworthii. Try a moss-
lined basket moved into protection during extreme cold snaps.
selense ssp. dasycladum
Shrubs, 3 to 12 ft. Flowers (March) are white to rose. This is a
variable subspecies and many forms have been collected from the
wild. Native to bouldery slopes and open pine forests from 11,000
to 13,000 ft. China
79/107 (rhaibocarpum) R 11269 (USDA 59197) BH (+10)
selense ssp. jucundum
Shrubs, 2 to 20 ft. Flowers (March) white to white flushed rose, rose,
or pink, sometimes with a crimson blotch. A geographically distinct
subspecies from NW Yunnan, China. Found on the edges of pine
woodlands and on rocky slopes from 10,000 to 12,000 ft.
82/138 (jucundum) BREM (0). Pastel rose flowers with a magenta blotch.
selense ssp. selense
Shrubs, 2 to 9 ft. Flowers (April-May) are pink to rose,
occasionally white to pale yellow, may be blotched. Found on
rocky alpine pastures by streams at 11,000 to 14,500 ft. China
76/312 ACB (0)
selense ssp. setiferum
Shrubs, 5 to 10 ft. Flowers (March) creamy white with red-colored flecks.
Possibly a natural hybrid between R. selense ssp. selense and
R. bainbridgeanum. Found in thickets and woodlands of pine from
12,000 to 13,000 ft. in China (NW Yunnan and SE Xizang).
65/521 (setiferum) WIND (0). Creamy white flowers with maroon flecks.
Upright and wide-spreading deciduous shrubs with a somewhat tiered
branching habit. This looks quite different from any other species
in the genus and is the only member of subgenus Mumeazalea.
The small and thin, shiny dark green, serrate-margined leaves
are usually hairy. The small white to white flushed pink flowers
have red spots and hang beneath the foliage in early summer.
A little known but distinct, graceful and attractive species
with bright fall foliage color for the woodland garden (also
tolerant of more sun). Native to Japan where it is found in
75/077 WAK (-5). Small white flowered form, pink and red
81/067 NA 44823-USNA (-5)
245sd96 YK#1046:RSBG ((5\R1\3). Grown from seed collected
wild at 1,400 ft. in Yamaguchi Prefecture, Honshu, Japan.
These are large vigorous seedlings grown from seed collected by Peter
Cox and myself on the S Yunnan/N Vietnam border at around 9,000 ft. in
1995. It bears a remarkable resemblance to the well-known species
R. hemsleyanum (which is only known from Emei Shan in Sichuan Province
450 miles to the north of this area!) with the same auriculate leaf
base and wavy margins. However, the leaves are much narrower and the
habit is more open. David Chamberlain has seen this same taxon in N
Vietnam and feels that we have finally found the long lost and little
known R. serotinum. Plants under this name have floated around for
years but appear to be mostly forms or hybrids of diaprepes. The new
growth emerges quite late in the spring (even under cover) on these
plants and so should miss the spring frosts which can be so damaging
to other species from such southern latitudes. Beautiful blue-green
foliage and rapid growth on this exciting new introduction.
562sd1996 SEH#242:RSBG (+5 to 0'\R1\8). These should have
large white and fragrant flowers sometime in late spring or
more likely, mid-summer. Note: I have offered this in past
catalogs as hemsleyanum affinity.
Semi-deciduous shrubs to 4 ft. Flowers (April-May) are pale pink
to white. Perhaps the smallest leaves and flowers in the genus.
Found on well-drained volcanic soils up to 6,000 ft. Japan
76/356 HSZ: WEB (-5)
79/173 WEB (-5). Form with delightful fuchsia colored
79/175 WEB (-5). Form with lavender purple flowers.
Deciduous shrubs to 15 ft. Flowers (July-August) are white or
occasionally pale pink. One of the latest to bloom and has a
pleasing sweet, clove-like scent. Found on coastal plains or the
edges of wooded swamps. SE USA
76/282 HTS 1227B: NA 7853-USNA (-5). Fragrant white flowers.
Collected from the wild in Jones County, Mississippi.
76/283 HTS 1280 - USNA (-5). Fragrant white form from
Screven County, GA.
76/284 (serrulatum var. georgianum) HTS 1265E: NA 7906-USNA
(-5). Wild collected in Charleton County, Georgia.
Dwarf shrubs to 1 ft. Flowers (May) are purple or pinkish or dark
wine-red. New growth is very bristly. Native to open rocky slopes
and alpine meadows at 12,000 to 15,000 ft. Himalayas
79/055 WEB. From seed collected on Mt. Everest.
Shrubs to 5 ft. Funnel-shaped flowers (variable flowering time)
are deep purple-red. Oblong to obovate leaves in pseudowhorls.
Dr. Hermann O. Sleumer states that this species is, "presumably a
more or less intermediate hybrid between R. abietifolium and R.
buxifolium var. robustum." A subalpine species found on
boulders, ridges, and among the dense vegetation of low trees and
shrubs at 9,000 to 10,000 ft. on the eastern side of Mt. Kinabalu
on the island of Boreno. Malaysia (Sabah).
87/048 GA 801154: RBG (+32).
Large upright-growing evergreen shrubs or small trees (generally
much smaller in cultivation) with attractive, smooth and peeling
reddish to pinkish bark. The leaves have a distinctive "chocolate-
brown" indumentum on the undersurface. The flowers (early spring)
are deep red with darker nectar pouches. A rarely grown but
extremely ornamental plant, one of the earliest blooming species
here at the RSBG. Native to a small area of S Tibet where it
grows in coniferous forest margins around 11,500 ft.
75/012 HIL (+5). Funnel-campanulate corollas of dark
75/238 WEB (+5). Cherry red three flowered trusses.
76/155 L&S#2751:RBGE (0\R2\3). Cardinal red flowers on this
1966 AM form.
76/193 RBG (+5).
Upright to low and mounding evergreen shrubs with shiny rounded
leaves. Little is known of this newly introduced species which
is quite closely related to R. dauricum with similar but generally
larger flowers in early to mid-spring and more fully evergreen
foliage. The flowers should be pale to deep rose-purple or pink
to rarely white. An exciting new introduction for the enthusiast
in colder and harsher climates. This should be quite cold and
even heat tolerant and seems quite amenable in cultivation so far.
Native to E Russia and Siberia? in a wide variety of altitudes
234sd96 RSBG ((25?\R1\2-5?). Grown from seed collected wild
in Russia. These have already started to bloom with shades
of deep rose-purple dominant.
Shrubs or small trees, 10 to 30 ft. Flowers (May-June) are cream
to clear yellow, sometimes with a red basal blotch. Lower leaf
surface with a light tan indumentum. Native to thickets, mixed
forests and open conifer woods at 8,000 to 12,000 ft. Burma,
73/255 KW 20838: WW - PHB (+10). Form with cream yellow
Shrubs, 4 to 23 ft. Flowers (May) are white or pinkish-violet.
Found on open ridges and dry, wooded hills at 2,700 to 6,900 ft.
80/102 BEN (0)
sikangense var. exquisitum
This beautiful species has only recently been introduced from the
Wumeng Shan of NE Yunnan Province, China where it is endemic. As seen
in the wild this should prove to be a popular and garden-worthy new
rhododendron for the home gardener as well as the collector. It forms
a large rounded evergreen shrub to small tree (in the wild) densely
covered with attractive foliage. The flowers are reported to be pink
to white with a deep red blotch and spots (mid-spring'). Quite common
in forests, open meadows and rhododendron thickets at around 10,000
to 12,000 ft. NOTE: We are also offering variety sikangense for the
first time this year (see below).
94/238 (var. sikangense) SB#9019:Berg ('10'\R1\3). Our first
offering of the typical variety of this species with narrower leaves.
This is the form from the Erlang Shan in Sichuan, China. Seed
collected by Warren Berg at 10,400 ft. Only a few available of
these beautiful large plants in 2-gallon containers
531sd1996 SEH#205:RSBG ('10'\R1\3). My own collection from
around 12,000 ft. These are exceptionally beautiful foliage plants.
sikangense var. sikangense
1994/238 sikangense var. sikangense SB#9019:Berg (-10\R1\3). Attractive
lanceolate leaves and white to pink flowers with a reddish blotch and
spots in mid-spring. Collected by Warren Berg on the Erlang Shan,
Sichuan, China. CRS#
Densely-branched and twiggy shrubs with semi-evergreen to evergreen
foliage. The flowers (late spring) are various shades of red to
pink or white, with dark spots on the upper lobes. A very heat
tolerant species. The primary component of the hybrid complex
known as the "Indica" or "Indian" azaleas so popular as indoor
potted plants. Native in scrub, open woodland and near water
from 1,000 to 9,000 ft. over a large area of E Asia including
China, NE Upper Burma, Hong Kong, S Taiwan, Laos, Thailand, and
the Ryukyu Islands of S Japan.
80/014 USNA 40245 (+5). Light pink flowers, and vigorous
80/018 USNA 43660 (+5). Simple bright pink flowers in this
83/218 Arb. des Barres (+5)
233sd95 PW#99:RSBG (+10?\R1\3). Grown from seed collected
wild at 5,570 ft. in Guizhou Province, China.
2001/008 simsii Valder#21:UC Berkeley (+10\R1\3). Evergreen azalea with
red to pinkish flowers. This clone with large leaves covered in long
golden hairs was collected wild in Thailand. Quite heat tolerant and
Shrubs to about 6 ft. Flowers (May) are white to rose with purple
flecks. Very limited distribution in the wild and not well
documented. Found among rhododendron thickets from 12,000 to
14,500 ft. China
76/168 (mimetes var. simulans) F 20428: RBG (0)
A spectacular new introduction. This species forms a large compact
and spreading evergreen tree with leaves up to one foot in length.
As the name of this new big-leaf implies, this is the Chinese or
eastern version of the closely related R. falconeri of the Himalayas.
R. sinofalconeri is native to a small area on the S Yunnan/N Vietnam
Border and differs in its broadly obovate leaves and eglandular
pedicels and ovaries. In addition, the indumentum on the undersurface
of the leaves is light brown in comparison with that of R. falconeri
which is dark or rusty brown. The flowers are borne in a large
rounded to flat-topped inflorescence and should be pale to rich
yellow. Appreciates some protection from the hot afternoon sun.
So far has proven to be hardier than R. macabeanum. Native to
broad-leaved forests from 5,250 to 10,000 ft.
553sd1996 SEH#229:RSBG (+5'\R1\7). Grown from my collection
of seed at 9,500 ft. on an exposed mountaintop in the Lao
Jing Shan of S Yunnan. Very vigorous, with beautiful foliage.
Shrubs, 3 to 12 ft. Flowers (May-June) are pink with yellowish
flecks. A very useful hardy species with soft pale colors. Leaves
with a thick tan indumentum below. Native to the edges of forests
from 4,000 to 7,500 ft. NE Turkey ; adjacent USSR
76/376 BERG ((25). Flowers pastel rose with darker lobes and gold-
83/210 ACB - BON (-25). Flowers pink
83/193 MEH ((25). Flowers pastel rose with gold-green flecks.
Shrubs or small trees, 6 to 25 ft. Flowers (March) are scarlet to
crimson with darker nectar pouches. Found in mixed forests from
8,500 to 12,000 ft. NE India, Bhutan, China
65/255 STR (+5). Form with brilliant red flowers.
75/061 (argipeplum) WAK (+5). Form with scarlet flowers.
A new introduction into cultivation, these are dwarf epiphytic
evergreen shrubs with thick and leathery, elliptic
to oblong leaves. The small but bright yellow flowers hang singly
or in pairs from the tips of the branches. They are bell-shaped with widely
flaring lobes. This is one of several closely related taxa newly
introduced from S Yunnan and adjacent N Vietnam. Many of these have only
recently been described as new species by botanists. This species
is visually distinguished from its close relatives by its very large leaves.
Quite hardy for a vireya – we have had this planted out in the
garden for many years with no damage. Our largest-leafed form. (+10?\R2\2)
Open and upright growing to compact evergreen shrubs or small trees.
The ovate to almost round leaves are dark green and smooth after
emerging an attractive glaucous blue-green. The exquisite saucer-
shaped flowers are pink or rose to white flushed pink in mid- to
late spring. To quote Peter Cox 'This superb plant is perhaps my
favourite species'. Best in cool summer regions with excellent
drainage. Native to rocky slopes and woodlands from 9,000 to
14,000 ft. in C Sichuan ; N Yunnan, China.
79/041 DUR (-5)
142sd95 RSBG ((10\R2\4). Seedlings from a hand-pollinated
cross here at the RSBG. This cross 76/245 (Brodick) x 77/663
(FCC form - Windsor).
365sd1997 97ARS#434:RSBG ('10\R2\4). Seedlings from a deep pink
form hand-pollinated by Peter Cox at Glendoick. Very few.
sperabile var. sperabile
Shrubs, 3 to 6 ft. Flowers (April) are crimson to scarlet. Needs
some protection in most gardens to produce good foliage and
flowers. Found among scrub and on cliffs at 10,000 to 12,000 ft.
China, NE Upper Burma
79/119 KW 7124 - Borde Hill (+10)
sperabile var. weihsiense
Evergreen shrubs with densely white tomentose branchlets. The lower
surface of the leaves is covered with a dense woolly white indumentum.
The tubular-bell-shaped flowers (mid-spring) are scarlet to crimson.
A rarely grown but attractive species with brightly colored flowers.
Best in light shade with excellent drainage. Native to NW Yunnan,
China where it occurs on cliffs and rocky slopes from 10,000 to 12,000 ft.
70/310 F#26478:Nymans (+5\R2\5). Rarely offered collector's item.
Form with deep scarlet flowers.
1995/087 sperabile var. weihsiense Glendoick (+5\R2\5). Long narrow
leaves with a white woolly indumentum beneath. Bright and waxy bell-
shaped crimson flowers in mid-spring. Requires excellent drainage.
Shrubs, 3 to 20 ft. Flowers (April-May) are white to pink with
purple flecks. A handsome hardy foliage plant, typically slow to
flower. Found in open forests and thickets from 11,000 to 15,000
64/145 COR (0)
67/688 Glendoick (0)
83/011 HLL (0). Form with white flowers.
sphaeroblastum var. wumengense
A newly introduced variety of the popular and beautiful R. sphaero-
blastum. This recently described taxon forms a compact rounded
evergreen shrub with extremely attractive foliage. This variety
differs from the typical in that the leaves are elliptic to oblong-
obovate in shape with a dense woolly indumentum of pale yellow-brown
hairs on the underside. The petioles (leaf stems) are also longer
in this variety and it occurs as a disjunct population 140 miles
from the nearest known population of the species. The flowers
(mid-spring) are white to white flushed pink, often with reddish
spots. Slow-growing but beautiful, requiring protection from the
hot afternoon sun and excellent drainage. Found only on the Wumeng
Shan of NE Yunnan, China where it occurs on open alpine slopes and
in Abies forest from 12,000 to 14,000 ft.
83/011 Larson ('10\R2\3). The typical form (var. sphaeroblastum)
with white flowers.
535sd1996 SEH#209:RSBG ('10\R2\3). My own collection made at
12,800 ft. from large, incredibly beautiful specimens. I am
pleased to offer these exquisite young plants which are
already developing their beautiful foliage (blue-green when
young). A true connoisseur's plant. NOTE: comparable specimens
from similar collections made in the same area will be
substituted if necessary.
Upright and open-growing evergreen shrubs with hairy branchlets.
The attractive leaves are heavily bullate (deep and prominent
veining) with hairs on the margins. The unique flowers (mid-
to late spring) are tubular in shape and held upright on the
stems. They range in color from orange to pink, reddish orange
or crimson with protruding stamens and style. An unusual species
with extremely 'unrhododendron-like' flowers. Suitable for planting
in hot and dry situations. Native to Yunnan and S Sichuan, China
where it occurs in dry pine forests and thickets from 5,500 to 8,500 ft.
69/834 DUN:WAL (+5?\R1\4). Vermilion flowers.
87/012 SBEC (+10).
87/014 SBEC (+10).
308sd1998 CCHH#8000:RSBG (+5\R1\4). These are cutting-grown
plants from our original plants grown from my collection of seed at
7,600 ft. in NW Yunnan, China from amazing 15 ft. specimens.
Small trees, 10 to 40 ft. Flowers (May) are white with a yellow
blotch and scented. Found in mixed forests and thickets at 1,500
to 9,000 ft. China
70/369 Kew - UBC PP (+10). White scented flowers on an open
wide ranging shrub.
Shrubs to 15 ft. Flowers (March-April) pale lilac, greenish
yellow in the throat and scented. Found at 9,000 ft. China
75/040 KW 20679: KEW (+20). Fragrant.
Rounded evergreen azaleas, often wider than high. The elliptic to
ovate leaves are covered with long soft hairs. The broadly funnel-
shaped flowers (mid-spring) are lilac-pink to purplish, typically
with spots and often fragrant. This evergreen azalea is fairly heat
tolerant but rare in gardens. Quite distinct and attractive. Native
to Japan where it occurs in forests and thickets. Formerly known as
65/447 'Linearifolium' (0\R1\4). The famous form of this
species with incredibly narrow 'crinkly' leaves that are
matched by the long and narrow lavender petals of the unusual
82/118 'Ladylocks' ('macrosepalum') Hill (+5\R1\4). Lovely
fragrant lavender flowers on this Polly Hill selection from
Shrubs to 3 ft. Flowers (variable flowering time) are bright to
dark red or orange-scarlet. Almost needle-like leaves that are a
tad over two inches long and only one sixteenth of an inch wide.
Found on the island of Borneo and common in the upper montane oak
forests on Mt. Kinabalu and also in mossy forests, on mountain
ridges, on river banks from 5,000 to 10,900 ft/ Indonesia,
85/046 FM: DC (+32)
Upright evergreen shrubs with pale brown peeling bark. The typically
elliptic to somewhat rounded leaves have a thin brownish indumentum
on the lower surface. Like the closely related R. eclecteum, the
tubular bell-shaped flowers of this species (early spring) are
incredibly variable in color, ranging from white to pink, rose or
various shades of red. They are often bicolored and may be heavily
spotted to unmarked. Rare in cultivation, this species can be
susceptible to powdery mildew (this has not been a big problem
here at the RSBG) but is useful for its very early blossoms.
Native to SE Tibet, Upper Burma and NW Yunnan, China where it
occurs in a wide variety of habitats from 10,000 to 14,000 ft.
67/684 COR (0)
414sd1998 CCHH#8137:RSBG (0\R2\3). Grown from my collection of
seed at 11,800 ft. on the Salween/Irrawaddy divide in NW Yunnan.
On a spring expedition to this same region it was noted that
most of the flowers were creamy yellow, though some superb
variations were present.
Large evergreen shrubs or small trees with an upright growth habit.
The tubular bell-shaped flowers put on a spectacular display in late
winter to early spring. These are deep red to crimson or scarlet
with blackish nectar pouches. The younger shoots and petioles are
covered with stiff bristles. A popular species desirable for its
luminous, late winter blossoms and attractive foliage. Easy in
cultivation and fantastic as a specimen or in the woodland garden.
Best in partial shade. Native to Sichuan and NE Yunnan, China where
it is found in thickets and on open slopes and cliffs from 7,000 to
73/270 Robbins ('5\R1\5). Large red flowers.
73/271 Greig ('5\R1\5). Bright red flowers.
75/159 Greig:Robbins ('5\R1\5). Large bright red flowers in early
spring on this stunning and popular species. The younger shoots and
leaf petioles are covered with dark bristles. Best in light shade.
75/178 GRE: WW (-5). One of our best forms with crimson
76/081 WEB (-5). Crimson flowers.
77/627 GRE - PM (-5). Form with crimson flowers.
77/627 GRE-PM (-5). Crimson flowers.
79/057 BN: WEB (-5).
82/125 RBG (-5). The best strigillosum at Edinburgh in Mr.
84/047 STN (-5). Deep red flowers.
493sd1996 SEH#155:RSBG ('5\R1\5). My own collection from
8,500 ft. in NE Yunnan, China.
Shrubs or small trees to 10 ft. Flowers (flowering time varies)
are white and can be fragrant. Easier to grow and flower than
R.orbiculatum, but appreciates some support. Found on the island
of Borneo in tropical rain forest from 5,000 to 6,500 ft.
80/004 DG (+32). Collected wild on Mt. Kanabalu, Borneo.
87/051 RBG 792883: CLL (+32)
Shrubs or trees to 45 ft. Flowers (February-March) are scarlet
with a few purple flecks. A recently collected (1965) species
related to R. thomsonii with similar red colored flowers and
peeling bark but with elongated leaves and more tubular flowers.
Found in mossy rain forests at 8,500 to 9,200 ft. NE India
77/636 C ;H 418: GLE - WEB (+10). A red flowered form. Blooms
80/170 RBG - LB (+10). Form with light red flowers.
Shrubs or small trees, 3 to 20 ft. Flowers (March) are crimson or
scarlet with large nectar pouches. Smooth, peeling purple bark.
Native to mixed forests and scrub at 11,000 to 13,500 ft. Bhutan,
83/038 BEN: TJ (+5) Form with deep red flowers.
Dwarf evergreen shrubs with smooth brown to red-brown peeling bark.
The dark green shiny leaves are typically glaucous white on the
lower surface. The small flattened bell-shaped flowers (early to
mid-spring) are greenish yellow to deep yellow. A choice species
rarely seen in cultivation. This is similar to, but quite distinct
from the plant we have sold for years here at the RSF as sulfureum
(1974/108 - now known to be R. dekatanum). Requires excellent drainage.
True sulfureum is native over a wide range of SE Tibet, Upper Burma
and W Yunnan, China. It grows on cliffs and rocks or as an epiphyte
from 7,000 to 13,000 ft.
74/108 Glendoick (+10). A hardy form with sulfur yellow
flowers, and eventually smooth brown bark.
501sd1998 CCHH#8236:RSBG (0'\R2\3). Grown from my collection
of seed at 11,000 ft. on the Cang Shan in W Yunnan, China.
Our first offering of this (relatively) newly described big-leaf species.
This is a recent introduction from Vietnam that was first collected as
both “sinogrande aff.” and “protistum aff.” as it shares characteristics
of both species. This has among the largest leaves of any species in
the genus and puts on an amazing foot and a half of growth each year.
Beautiful pure white flowers with a strong red blotch. As far as is
currently known, this and the more widespread sinofalconeri are the
only big-leaf species in Vietnam. An amazing plant that is probably
similar in hardiness to sinofalconeri but I am guessing slightly
less so as it comes from a somewhat lower elevation. (+5?\R1\9)
Tropical shrubs to 6 ft. Flowers (flowering time varies) are
white to creamy yellow. The dramatic large leaves are covered
with rough scales. Large scented flowers appear on mature plants.
Native to Papua New Guinea at 5,000 to 10,000 ft.
78/094 FM (+32). Three large flowers per truss, the petals
form a cream tube that is soft pink on the lobes.
83/069 SCHI (+32\R2\?).
Large shrubs, 15 to 35 ft. Large leaves up to one foot long. Flowers
(January to April) pale pink to pale mauve-pink with no basal blotch.
A beautiful large, early flowering species which performs best in
woodland conditions. Hardy even in the eastern half of the USA as
far north as Boston. Native to China(Shaanxi, N Sichuan, Hubei,
Guizhou, and Guangxi) where it grows in forests and bamboo groves from
5,000 to 8,000 ft.
65/348 Caerhays - UBC PP (0). A typical form of this
handsome small tree.
77/205 VANW ((10). Large pale pink flowers with maroon flecks.
79/120 ('Seventh Heaven') Wilson 1232: BH (-10). Flowers
white suffused reddish-purple.
82/197 AC (-10)
Large rangy shrubs with spectacular large fragrant flowers. These
are pure white with a yellow throat and in the shape of a trumpet-lily.
Very similar to the closely related R. lindleyi but generally easier
to grow. Attractive red-brown peeling bark. Requires excellent drainage
and frequent pinching as a young plant (to reduce legginess if so desired).
Native to the east of R. lindleyi where it is found as an epiphyte in
tall trees or terrestrially on cliffs and rocks. It occurs from 6,000
to 12,000 ft. in SE Tibet, NE India (Arunachal Pradesh), N Burma and
W Yunnan. A stunning flowering plant.
237sd1998 RSBG (+15\R2\6). These are seedlings grown from the AM
form 'Cliff Hanger' selfed by Ted Millais.
Slow-growing and compact but upright evergreen shrubs with stout
branches. The lower surface of the leaves is covered with a thick
felted brownish indumentum. The flowers (mid-spring) are white with
reddish spots. A beautiful foliage plant with stunning new growth
like furry white candles striped longitudinally with bright green.
Requires a cool position with good light and excellent drainage.
Full sun is not advised. One of my favorite species, the foliage is
fragrant on a warm day. Native to W Yunnan, China where it occurs
on open slopes from 10,000 to 13,000 ft.
65/292 BEN - UBC (-10). Form with cream colored flowers with
82/139 BRP (-10).
83/029 TJ (-10).
518sd1998 CCHH#8254:RSBG ('10\R3\3). Grown from my collection
of seed at 12,200 ft. on the Cang Shan. Rarely available wild-
origin source of this classic choice species. These should
develop a thick and dark indumentum as they age.
Low growing azalea. Flowers are red to purplish red to pink and
occasionaly white. Rare in the wild and in cultivation.
Considered one of the parents of the Satsuki Azaleas. Found on
the islands south of Kyushu at low elevations from sea level to
rocky hillsides. Japan
80/014 (eriocarpum) USNA (+10). From seed collected on Yaku
Low dense shrubs which can reach 3 ft. Flowers (April) are
purplish-blue, violet, rose or rarely yellow. A species that is
rare in cultivation and forms a dense ground cover. Found on open
alpine slopes and bare scree from 11,000 to 15,000 ft. NE Burma,
83/135 RBG (0)
Upright to spreading evergreen shrubs with reddish branchlets.
The small leathery leaves are covered with scales. The widely
funnel-shaped flowers (mid-spring) are whitish to rose, lavender
or purple, usually with reddish spots. An uncommon species in
cultivation and rarely offered. Quite variable but generally
easy and floriferous. Native to NW Yunnan & S Sichuan, China
where it occurs in various open habitats from 7,000 to 12,000 ft.
70/422 RBGE ((5\R1\5). White flushed rose-purple flowers.
This smaller growing (but bonsai tree-like) species has extremely
narrow, deep green and shiny, “grass-like” leaves unlike
any other rhododendron. The bell-shaped flowers are pure white.
As the name implies, it actually looks like a small yew tree. Always
attracts attention – one of the most unusual of all species. (+32\R2\2)
Bushy dwarf shrubs to 3 ft. Flowers (April-May) are lavender to
purple, or rose-pink. Very common and variable in the wild and
relatively easy to cultivate. Found on open rocky slopes and
cliffs at 9.500 to 16,000 ft. China
77/757 F.21250 - Windsor (-5)
77/758 F.21377 - Windson (-5). One-half inch flowers of soft
mauve in this selection.
77/759 KW 4102: WGP (-5). From seed collected by F. Kingdon
Ward during his 1921 expedition to Yunnan and Sichuan.
80/006 (drumonium) F.15210 - Castle Howard (-5). Although
many clones seen are labeled as such, this is a true form.
temenium var. dealbatum
Dwarf shrubs to 4 ft. Flowers (April) are white to deep rose-pink
in lax trusses. Grows among scrub, on rocky cliffs, and in open
moorland from 12,000 to 15,000 ft. China
76/196 (glaphyrum) RBG (0)
temenium var. gilvum
Dwarf shrubs to 4 ft. Flowers (April) are pale yellow to yellow
tinged with pink. Found on cliff ledges, among scrub, and in
thickets at 12,000 to 15,000 ft. China
79/165 (temenium ssp. chrysanthum 'Cruachan') GLE (0)
Shrubs, usually only to 5 ft. Flowers (April-May) are pink to
carmine-red, rarely white. Found on rocky slopes and scree at
8,000 to 14,000 ft. India, NE Burma, China
65/257 KW 20844 - Stronachullin (+10). Clusters of three-
quarter inch carmine rose bells in late April on a shrub of
This is a recent introduction that appears to be a new species,
possibly related to, or maybe a Vietnamese form of, the widespread
tephropeplum from the Sino-Himalaya. This is a collection from
N Vietnam and many of the new introductions from that region are
turning out to be much more tolerant of cold temperatures than
their northern counterparts. This possibly new species features
interesting narrow and brownish-silvery scaly foliage and clusters
of narrowly tubular pink to pale pink flowers.
NOTE: This was sold in the past as “xanthostephanum aff.” but we
have since flowered the very precocious seedlings and they are
pinkish and much more similar to tephropeplum. (Actually, there
is also a “xanthostephanum aff.” with yellow flowers that we have
flowered from the same region.) Almost certainly a new species
and yet another mystery plant from this exciting part of the world.
(+5\R1\2) RSBG#105sd2007 DJHMV#133
Shrubs, 6 to 12 ft. Flowers (June) are white tinged with pink and
slightly speckled. A very distinct late flowering species with
remarkable stiff foliage and white-to-green candles of new
growth. Leaves are indumented. Found in woodlands from 9,000 to
10,000 ft. China
66/605 CAE (-5). Form with evenly spaced trusses of white
66/617 RBGE ((5). Rose buds opening white with maroon flecks.
thomsonii ssp. lopsangianum
Shrubs 2 to 6 ft. Flowers (April) are deep crimson. Small oval
leaves with tubular bell-shaped blossoms. Found on open hillsides
and rocky slopes at 8,500 to 14,000 ft. China
77/696 BRO (+5). Crimson flowers.
thomsonii ssp. thomsonii
Large upright-growing evergreen shrubs or small trees with tan to
reddish, smooth and peeling bark. The bell-shaped flowers (mid-
spring) are dark shades of red to crimson, sometimes with flecks
and a brightly colored calyx. The leaves are orbicular in shape
and usually an attractive glaucous blue-green in color. Can be
afflicted with powdery mildew and may be partially defoliated in
extreme cases although we have little trouble here at the RSBG.
A classic and highly ornamental species which should be in every
garden. Found in various montane habitats from 8,000 to 14,000 ft.
in the eastern Himalayas.
64/058 LAR:PHET:WAL ((5\R2\5). Red flowers.
76/716 L ;S 2847 - RBG (-5). A hardy clone with unusually
large leaves and large red flowers with red calyxes.
75/237 TRW: WEB (0). Warren Berg's choice as the best pure
red thomsonii from the gardens of Cornwall.
80/082 GLE (0)
129sd95 RSBG ((5\R2\5). Grown from seed collected wild from
superior forms in Kyong Nosla, Sikkim by Britt Smith.
558sd1997 SEH#572:RSBG ('5\R2\5). My own collection from
10,500 ft. in the Sikkim Himalaya from a plant with a pale
tomentosum 'Milky Way'
The best form of this species I have ever seen, Rhododendron 'Milky
Way' is a superior selection of a species formerly included in the
genus Ledum (as Ledum palustre). Recently, the genus Ledum was
'lumped' into the genus Rhododendron, adding six species to this
already massive and variable group. 'Milky Way' covers itself with
rounded trusses of pure white flowers in mid-spring. While each
individual saucer-shaped flower is relatively small, each truss is
composed of six or seven individual trusses containing up to 20
flowers each. A full-grown plant will ultimately reach about three
feet in height with a five-foot spread, well-branched, with foliage
to the ground. The attractive evergreen foliage is deep green with a
reddish brown, woolly indumentum on the lower surface and young
stems. 'Milky Way' is a tough and adaptable plant but performs best
in a moist organic soil in sun or light shade. Probably hardy to
around '30' F. See the October 1999 issue of the RSBG Newsletter
for additional information.
90/090 RSBG ('30\R1\3). A fantastic plant for almost any garden.
Dwarf bushy evergreen shrubs with a glandular and long reddish
brown woolly indumentum on the stems. The linear to narrowly
elliptic leaves have a strongly recurved margin and are covered
with a dense woolly brownish indumentum on the underside. The
small white flowers (mid-spring to early summer) are borne in
a dense rounded inflorescence. An extremely hardy, widespread,
variable and floriferous species. Tolerant of fairly exposed
sites and wet soils. Formerly included in the genus Ledum which
has recently been "sunk" into Rhododendron. Native to bogs,
coniferous forests and similar boreal habitats in N Europe and N Asia.
127sd96 ("Ledum angustum") JJH9510172:RSBG ((35?\R1\3).
Grown from seed collected wild at 7,900 ft. in the Altai
Mountains of S Siberia & Mongolia. Extremely narrow leaves
on this taxon which is still in taxonomic limbo. Collected
from "tiny shrublets with white fragrant flowerheads".
Densely-branched shrubs with slender shoots. The foliage of this
evergreen azalea is deciduous to evergreen, often turning purple in
the autumn. The flowers (mid- to late spring) are purplish pink to
rose or lilac-purple, often with darker flecks, rarely white flushed
pink. A good species for warm climates. Plants formerly known as
komiyamae should be quite hardy. Common in C ; S Japan on exposed
slopes or in forests from sea-level to 5,000 ft.
79/016 USNA 40870 (0). Lavender-pink flowers with ten stamens,
this form from seed collected on Ashitaka Yama in Japan.
79/087 ('Barbara') HIL: LJP (0). Vibrant pink flowers
traillianum var. dictyotum
Small shrubs, 4 to 5 ft. Flowers (May) are white and sometimes
spotted with crimson. Considered a rare plant in cultivation.
Found on scrub-clad slopes and on margins of conifer forests from
11,000 to 14,000 ft. China
65/508 (dictyotum) Rock 18437: WGP (0). Form with white
75/084 (dictyotum 'Katmandu') Exbury (0). Softly grained
indumentum and flowers of fine white-blotched and spotted
crimson. An Award of Merit form, 1966.
traillianum var. traillianum
Stout-growing upright evergreen shrubs or small trees. The leaves
have a distinctive 'pebbly' tan to brownish indumentum on the lower
surface, the upper surface is smooth and shiny green. The flowers
mid-spring) are white to white flushed rose or pinkish, often with
spots and/or a blotch. An uncommon but not difficult member of this
popular subsection. Native to China (SE Tibet, SW Sichuan ; W Yunnan)
where it is a common species in coniferous forests and open areas
from 10,000 to 15,000 ft.
76/058 Nelson:Berg ('10\R1\4). Best in light shade.
92/100 SB#8301:BERG ((10\R1\4). This clone grown from seed
collected wild in Sichuan at 12,000 ft.
Large upright-growing evergreen shrubs with distinctly bristly
branches. The new growth and the upper surface of the leaves are
also densely covered with soft bristles. The flowers (late spring
to early summer) are similar to those of R. augustinii but generally
much darker in color (in cultivated forms). They are dark blue-
purple to reddish or pale purple, often with reddish, greenish or
brown markings. Quite attractive and valued for it's late blooming.
Native to W Sichuan, China where it is often common in forests from
5,250 to 10,350 ft.
69/723 BRA.L:WAL ((5\R1\6). Dark red-purple flowers with burgundy
75/169 'Tower Court Form' Wales Wood (-5). Named for its
covering of bristles on stems, petioles and pedicels. Flowers of
a rich purple.
76/059 JHC (-5). Form with deep royal purple flowers.
76/346 KSG (-5). Form with mid-May flowers of deep purple
with green blotch.
Deciduous shrubs to 5 ft. Flowers (April-May) are yellow or
greenish orange-yellow. Bronze colored new growth. Native to
rocky cliffs and scrub at forest margins from 8,000 to 11,000 ft.
N Burma, China
78/091 BAR - CHP (0). Form with greenish-yellow flowers.
80/160 (oulotrichum) P. Miller (0).
Upright or sometimes wide-spreading but compact evergreen shrubs
with smooth and peeling whitish to tan bark. The small narrow
leaves are quite scaly beneath and fragrant. The white to rose
flowers (mid-spring) are in small rounded clusters reminiscent of
a Daphne, narrowly tubular in shape with spreading lobes. A
beautiful and usually free-flowering species which is
unfortunately difficult to propagate. Requires excellent drainage
and good light. One of the most asked for species in the garden.
Native to N Yunnan and SW & C Sichuan, China where it occurs in
forests and on open slopes from 10,000 to 13,000 ft.
73/283 FR (-5). Form with light pink flowers.
80/164 'Rae Berry' BOV:GAM ((5\R2\3). Deep pink flowers.
82/164 JCB (-5). Hardy form with light pink flowers.
Subsection Triflora (species nova) JN#11022
An unknown, almost certainly new species, collected far to the east
of where most Triflora species are known to occur. Noted to have
cream to yellow flowers on a very compact plant. (-5?\R1\4)
Subsection Triflora (species nova) CGG#14068
An unknown, almost certainly new species, collected far to the
east of where most Triflora species are known to occur. The plants
were the typical large and bushy Triflora with lavender to red-purple flowers. (0\R1\7)
Subsection Triflora (zaleucum affinity – probably species nova?) CDHM#14573
An unknown, almost certainly new species,
collected far to the east of where the species zaleucum is known to occur
but sharing the very distinct, glaucous white-waxy underside
of the leaves as seen in that species. I have not seen this in flower
but the plants were the typical large and bushy Triflora in form and
habit. Foliage quite shiny on top, a most remarkable collection. (0\R1\7)
triflorum var. triflorum
Upright evergreen shrubs typically with smooth and peeling mahogany
to reddish bark. The leaves are smooth on the upper surface, quite
white glaucous to pale green on the lower. The widely funnel-shaped
flowers (late spring to early summer) are cream to various shades of
yellow, with greenish spots and often flushed shades of red. Worth a
place in the garden for its attractive peeling bark and glaucous
foliage alone. A widespread, common and variable species native in
the eastern Himalayas from E Nepal into the N Burma/SE Tibet frontier.
It occurs in a wide variety of habitats from 7,000 to 13,000 ft.
70/026 (triflorum var. mahoganii) FR (+5). Form with light
yellow flowers and a mahogany blotch.
515sd97 SEH#529:RSBG (+5?\R1\4). Grown from seed collected wild
at 9,500 ft. in the Sikkim Himalayas from plants with exceptionally
beautiful peeling mahogany bark and glaucous white leaf undersides.
Beautiful blue-green young leaves.
575sd1997 SEH#589:RSBG (+5'\R1\4). My own collection from an
exposed sunny slope at 8,500 ft. in the Sikkim Himalaya
Shrubs, 3 to 20 ft. Flowers (May) are cream to yellow with
greenish yellow or dark red spots. Native to forest margins,
moist hillsides and cliffs at 9,000 to 12,000 ft. Himalayas
triflorum var. bauhiniiflorum
Shrubs, 2 to 15 ft. Flowers (May) are greenish-yellow to yellow
and with darker greenish-yellow spots. The corolla is flat and
saucer-shaped in this variety. Found in the states of Nagaland
and Manipur in eastern India. Common on hillsides at 8,000 to
9,000 ft. E India
73/026 (bauhiniiflorum) FR (+5). Lemon-yellow flowers.
triflorum var. triflorum
Shrubs, 3 to 20 ft. Flowers (May) are cream to yellow with
greenish-yellow or dark red spots. The corolla is widely funnel-
shaped in this variety. Native to mixed and conifer woodlands,
bogs, on cliffs, and in bamboo or rhododendron thickets at 9,000
to 12,000 ft. Nepal, NE India, Bhutan, N Burma, SW China
80/097 KW 6409: (+5)
Low-growing evergreen shrubs with tiny scaly leaves. A rare and
newly introduced taxon which is closely related to the well-known
hippophaeoides but differs in its smaller leaves and fewer stamens.
Previously known only from NE Yunnan along the Yangtze River at
around 9,500 ft. It was collected in 1990 and again in 1995 from
adjacent areas on the Sichuan side of the Yangtze River. These
collections are considered to be intermediates between
hippophaeoides and tsaii. I am quite impressed with the performance
of this new taxon in the garden. It blooms over a long period with
lavender to pale purple flowers and is quite easy to grow.
389sd1996 SEH#040:RSBG ('10'\R1\2). Grown from my collection
of seed at 11,150 ft. in the Daliang Shan, S Sichuan, China.
Shrubs, 3 to 10 ft. Flowers (April) are white to cream to pale
pink with or without crimson spots. Striking wooly branchlets
and leaves with dense fawn to rust-colored indumentum. Found on
open hillsides and in mixed forests from 11,000 to 14,500 ft. SW
China, NE India
66/653 GREI:WAL (0). Carmine-rose in bud opening to white flowers.
75/150 NEL:ROBB (0). Deep carmine-rose in bud opening to white
flowers with magenta flecks.
77/665 Windson (0). A clone of compact habit with deep pink
buds and eventually almost white flowers. An Award of Merit
82/180 TJ (0).
84/043 STN (0). Creamy white flowers from pink buds.
Dwarf mounding to prostrate evergreen shrubs with long golden hairs
covering the branchlets and tiny elliptic leaves. The narrowly bell-
shaped flowers (late spring to early summer) are white and in small
clusters. Not particularly showy but an interesting dwarf azalea.
Formerly included in a separate genus as Tsusiophyllum tanakae.
Quite distinct but rarely seen in cultivation. Native only to
central Honshu, Japan where it is quite rare on open mountain slopes.
76/353 Suzuki:Berg ('5\R1\2). This form upright in habit. White
Shrubs or small trees, 5 to 20 ft. Flowers (July) are white,
sometimes flushed pink, with greenish flecks. An Excellent
foliage plant that needs a moist, shady spot to succeed. Native
to spruce forests from 3,500 to 6,000 ft. NE Turkey and adjacent
76/061 JC (0).
uniflorum var. imperator
Prostrate shrubs rarely attaining 1 ft. in height. Flowers
(April) are purple to pinkish-purple. Narrow funnel-shaped
flowers on a ground-hugging mat. Found on bare cliff ledges at
10,000 to 11,000 ft. NE Burma.
65/422 (syn. imperator) WAK (0). Rose-purple flowers.
uvarifolium var. uvariifolium
Large upright-growing evergreen shrubs or trees with stout
branches and large shiny dark green leaves. The impressive
new growth is covered with a plastered to woolly, silvery white
indumentum which is retained on the underside of the leaves.
The flowers (early to mid-spring) are white to pale pink,
usually with crimson flecks and a large purple blotch. A
common and often dominant species where native in the wild.
Found in various montane habitats from 7,000 to 14,000 ft.
in E Arunachal Pradesh and China (NW Yunnan & SW Sichuan).
93sd352 RSBG (0 to (5\R1\5). Grown from seed collected in
76/250 (uvarifolium var. griseum) BEN (-5)
Compact shrubs to 4 ft. Flowers (March-April) are bright yellow.
Very distinct dark hairy leaves and richly colored flowers on a
tender shrub. Found growing on cliffs and stony slopes from 9,000
to 12,000 ft. NE Burma, China.
65/391 Bodnant (+10). Bright yellow flowers, small leaved
and slight stature. An Award of Merit form, 1936.
This taxon is obviously related to R. valentinianum but appears to
be distinct enough to warrant at least subspecific status. The leaves
of this new collection are much larger than those of the typical species,
up to three inches in length. They are similar in shape but heavily
bullate on the upper surface. The leaves also have long hairs fringing
the outer edge for an overall stunning foliage effect. The deep purple-
brown bark is smooth and exfoliating. Really worth growing for foliage
and bark alone. Best of all, this new introduction has the deepest waxy
yellow, bell-shaped flowers of any rhododendron I have seen. Requires
exceptionally well-drained soil, should be relatively hardy. Found in
S Yunnan and adjacent N Vietnam where it occurs as an epiphyte and on
steep banks at around 9,000 ft. A beautiful plant.
559sd1996 SEH#235:RSBG (+5'\R2\4). Grown from my collection of
seed at 9,000 ft. in S Yunnan, China. One of my favorite introductions
and already one of my very favorite rhododendrons
valentinianum var. oblongilobatum aff./species nova? DJHMV#106
The most compact-growing and dwarf representation of this very confusing
species complex – this is the “alpine form” as known from the top of
the highest mountain in N Vietnam. Masses of deep yellow waxy flowers
with hairy, deeply bullate, glossy green leaves. Much smaller and more
compact than its close relative from just across the Red River in
S Yunnan – the newly named valentinioides. Smooth and peeling reddish-brown bark.
So far, this has proven to be quite hardy for a Maddenia. A stunning
foliage plant with the darkest yellow flowers I have seen in a rhododendron.
Grown from seed collected in the wild. A truly dwarf, deep yellow-flowered,
and relatively hardy Maddenia. Sure to become one of the most popular of
the new introductions in years to come. (+5\R2\5)
Large upright deciduous shrubs with distinctive elliptic leaves
tapering at each end. Brilliant fall color in most climates. The
widely funnel-shaped flowers (early to mid-spring) are strikingly
beautiful in shape, poise and color. The typical form is pale pink
to deep rose but white forms are not unknown in the wild. Best in
sun with a moisture-retentive soil but quite adaptable and hardy.
Although easily cultivated and quite common where it occurs, the
Pinkshell Azalea has a very limited range in the wild. It is an
interesting species not closely related to any other Rhododendron.
Found only in the mountains of western North Carolina, USA where
it occurs in a wide variety of habitats from about 1,000 to 4,000 ft.
75/032 'White Find' LaBar ('20\R1\5). The famous pure white
selection of this ornamental species. Only a few.
78/014 LF-GBN (-15). Form with rose-pink flowers.
81/077 BIL (-15). One of the best pink forms of this eastern
Large and vigorous, but often compact-growing evergreen shrubs with
smooth and shiny reddish brown bark. The large fragrant flowers are
white, often with a yellow blotch and typically frilled or wavy along
the outer part of the lobes. Quite variable in terms of blooming
season and requiring excellent drainage. Native to S Burma, Laos,
Thailand and Vietnam where it occurs from 3,000 to 8,000 ft. as an
epiphyte, on rocks and cliffs or dry evergreen forests.
74/001 'Ashcombe' (Cubitii Group) Windsor (+25\R2\6).
Magnificent large white flowers with an orange-yellow blotch on
this 1962 FCC clone.
81/127 SA-EK (+20). Light chartreuse buds open white flushed
yellow in the throat.
Compact evergreen shrubs with attractive recurved leaves. The new
growth is coated with a thin silvery indumentum when it first emerges.
This is retained as a thin brownish indumentum on the lower surfaces
of the leaves. The flowers (late spring to early summer) are scarlet
to reddish orange with darker nectar pouches. A very distinctive and
attractive species with no close allies. Native to a small area of the
Tsangpo Gorge in SE Tibet, China from 8,000 to 8,500 ft. in thickets,
swamps and on rocks. A collector's species valued for its attractive
red flowers late in the season.
65/381 RBGE (0\R1\3). Bright red tubular flowers.
69/833 GRE-MVW (+5). Crimson flowers.
venator affinity (species nova)
A new, soon to be named species from a previously unexplored region
of the eastern Himalaya. This appears to be close to the rare
venator which had only been found previously in the Tsangpo Gorge
of adjacent SE Tibet. Long narrow leaves with the stems and new
growth densely covered with bright red bristles. Red bell-shaped
flowers in mid-spring. (+5?\R1\4)
Large rounded evergreen shrubs or small trees with smooth green
leaves. The flowers (mid-spring) are typically pale pink to rose
but can be white or pinkish purple and most forms have crimson
flecks. A widespread, common and variable species in the wild.
A free-flowering and easily grown species, beautiful in blossom.
Native to China (SE Tibet, Yunnan, Sichuan & Gansu) from 9,000 to
14,000 ft. in a wide variety of habitats.
69/812 RL-MVW (-5). Form with pink flowers.
78/112 Dexter - UW Arb. (-5).
79/152 HSM 13976: GBG (0).
79/144 (vernicosum f. euanthum) F#5881:RBGE ((5)
504sd96 SEH#175:RSBG ((5?\R1\5). Beautiful vigorous plants grown
from seed collected wild at 9,200 ft. in NE Yunnan. The plants
from which this seed was collected were in a population far to
the east of where R. vernicosum has previously been recorded.
They were quite distinct with rounded leaves similar to those
of R. orbiculare. Should prove to be a fascinating new introduction.
(Possible Hybrid of R. flavidum)
A shrub to 3 ft. Flowers (May) are deep lavender. Small leaves on
plant formerly recognized as a species. Collected from W Sichuan
art 10,000 ft. China.
65/461 Wisley (0). Deep lavender flowers.
Small and compact evergreen shrubs up to four or five feet. The new
growth is an intense red-purple, quite stunning. Small, obovate to
somewhat elliptic, thin textured and smooth leaves. The tubular bell-
shaped flowers (late winter to early spring) are bright red. A distinct
and attractive species. It was thought that the real thing was not in
cultivation any longer but I was able to verify our only clone as true
vialii. This has since been returned to Great Britain from whence our
plant was received. Obviously extremely rare in cultivation, this is
an unusual garden plant which is much hardier than one would expect.
It has survived many years outside here at the RSBG and even flowers.
Native to central and S Yunnan, China where it occurs in thickets from
4,000 to 6,500 ft.
1981/078 Goteborg B.G.:Borde Hill (0'\R1\4). Our first
offering(') of this rare species with red flowers. Should be
heat and sun tolerant.
virgatum ssp. oleiofolium
Shrubs to 5 ft. Flowers (March-May) are white or pink. A
Subspecies with smaller paler flowers that tolerates a warm, dry
site. Found on open scrubby sites from 6,500 to 13,000 ft.
84/072 (oleiofolium) KW 6279: Brodick (+15)
virgatum ssp. virgatum
Low mounding evergreen shrubs with small lanceolate leaves. The
funnel-shaped flowers are white to deep pink in mid-spring. A rarely
offered but floriferous and drought tolerant species for sun or
shade. Known to bloom as a one-year old plant. Quite common in
the eastern Himalayas where it occurs from 8,000 to 12,500 ft.
in various exposed habitats.
65/404 Crarae (+10). Rose pink flowers.
66/672 R.183 or 185 - WW (+10).
80/038 Brodick (+10). White flowered form.
521sd1997 SEH#535:RSBG (+10\R1\3). Grown from my collection of
seed at 7,500 ft. in the Sikkim Himalaya.
Compact and upright evergreen shrubs with bristly branches. The
delicate obovate leaves are bright blue-green and often have bristles
on the margins. The widely flaring, funnel bell-shaped flowers (early
to mid-summer) are yellow with greenish spots. An unusual but
attractive late-blooming species with beautiful foliage. Native only
to SE Tibet where it occurs in boggy areas and on alpine slopes from
10,000 to 11,000(') ft.
74/111 'Doshong La' KW#5829:Glendoick (0\R1\3). Yellow
flowers with rose tips and olive-green flecks in this 1972
Award of Merit form.
390sd1997 CC#7557:RSBG (0\R1\3). Grown from seed collected
wild in SE Tibet by Peter ; Ken Cox at 11,800 ft. Stunning
blue-green foliage on these large seedlings.
Shrubs, 2 to 8 ft. Flowers (April-May) are coppery red to
coppery-orange with darker nectar pouches and flecks. Unusual-
colored flower on a species rare in cultivation. Found on cliff
faces near streams and waterfalls at 9,000 to 11,000 ft. China
65/297 L ;S 6567: GLN (0). Form with unique copper-orange
Deciduous shrubs to 10 ft. Flowers (June) are reddish-purple to
purple with darker flecks. Native only in southern areas on the
island of Kyushyu. Recently confirmed specific status by D.F.
Chamberlain and S.J. Rae in the Edinburgh Journal of Botany,
Volume 47, No. 2,1990. Found in upland forests. Japan
77/028 MG (0)
Deciduous and often stoloniferous shrubs which can become quite large
in the wild. The long tubular flowers with flared lobes (late spring
to early summer) are white to light pink with a spicy fragrance. Yellow-
orange autumn color. Found in low marshes, on river banks, and
in mixed forests. Valuable for its late bloom time, fragrant flowers
and tolerance of a wide variety of cultural conditions. Commonly
called the Swamp Azalea, this species is native from Maine to Florida,
west into Oklahoma and SE Texas, USA. Now includes the former
species coryi, serrulatum and oblongifolium.
76/280 ('oblongifolium') USNA ('10\R1\5). This clone
collected in Tyler Co., Texas.
76/285 ('serrulatum var. georgianum') HTS#1265C:USNA
('10\R1\5). This clone collected wild in Charleston Co., South
76/287 (syn. viscosum var. aemulans) HTS 1104: USNA (-15).
Propagated from a plant collected in Henry Co., AL
76/288 HTS 1325A: NA 10086-USNA (-15). Collected from the
wild in Lebanon County, Pennsylvania.
78/110 KWG (-15). Propagated from a plant collected in Anne
Arundel Co., MD
80/025 KWG (-15). Propagated from a plant found in Hyannis,
86/026 'Delaware Blue' HILL ((15\R1\6). This clone selected
and named by Polly Hill from a wild population in Delaware
for it's glaucous-blue foliage. Our first offering of this
87/017 viscosum 'Delaware Blue' Hill (-15\R1\5). An excellent
blue-leaf selection of this eastern azalea made by Polly Hill.
Highly fragrant white flowers in early to mid-summer. Great in sun
or in the woodland garden.
90/SD4 Seedling BOW.
90sd006 Seedlings ( grown from seed collected at Bowman's Hill
Wildflower Preserve, Washington Crossing, Pennsylvania.
225sd1998 98ARS#575:RSBG ('15\R1\5). Grown from seed collected wild
in Plymouth Co., Massachusetts.
Large upright-growing evergreen shrubs. The flowers (mid-spring) are
mauve, lavender, rose-purple, pink or white, sometimes speckled purple
or brown. Handsome shrubs closely related to R. campanulatum but
glabrous or with a sparse dark brown indumentum on the undersides of
the leaves, shiny and dark green above. Grows in mixed forests of
birch, spruce, and fir, or on open rocky slopes among scrub and
juniper from 9,000 to 14,000 ft. in the eastern Himalayas.
75/080 LS ;H 17527: WAK (-5). Form with delicate lavender
75/128 SH#6658:RBGE (0). Pastel rose-purple flowers.
94/073 BB#8837:Berg ('5\R1\4). Cuttings from a clone grown
from seed collected by Warren Berg in Bhutan at 12,200 ft.
288sd95 95ARS#469:RSBG (0 to (10?\R1\4). Nice large plants from
seed collected wild by the Danish Sikkim Expedition (#144) at
11,800 ft. in Sandakphu, West Bengal, India.
495sd1997 SEH#508:RSBG ('5\R1\4). My own collection from
Sandakphu in the West Bengal, Indian Himalaya at 11,000 ft.
Shrubs to 20 ft. Flowers (April) are pale lilac to violet to
pink or white, sometimes spotted. Discovered by J. Hooker
in 1849. Native to birch and spruce forests and juniper
scrub at 9,500 to 13,000 ft. Himalayas
Shrubs to 10 ft. Flowers (April-May) are creamy-white with a
greenish blotch and may have a spicy scent. Native to the
Arunachal Pradesh territory of India. Rarely epiphytic in trees
or terrestrial in forested ravines and on rocky cliffs at 5,000
to 7,000 ft. NE India
87/060 RBG 774055-RBG (+32)
wardii var. wardii
Large upright-growing evergreen shrubs or small trees with rounded
smooth green leaves, often glaucous beneath. The saucer-shaped
flowers (mid- to late spring) are yellow to sulfur-yellow and may
have a maroon or purple basal blotch. A parent of many beautiful
yellow-flowered hybrids, in its finest forms this species is itself
an exceptionally beautiful garden plant. Susceptible to powdery
mildew which may partially defoliate the plant in a severe case
although we have had little of this at the RSBG. Native to Sichuan,
Yunnan, and SE Tibet, China. Common in a wide variety of montane
habitats from 9,000 to 14,000 ft.
65/327 'Meadow Pond' LS ;E 15764: WGP (-5). Received an Award
of Merit in 1963 for its primrose-yellow flowers with a
69/096 L ;S 15764: WGP (-10)
70/059 (=73/296) KW#4170:EXB:PHET ((10). Orange-yellow buds open
to yellow flowers.
73/296 KW 4170: EXB: CHP (-10). An early season, unblotched,
clear yellow form. Our hardiest form.
74/044 LS ;T#5679:RBGE ('10\R2\4). This clone should have yellow
flowers with a reddish blotch.
75/129 SH 6596 (-5). This form with small rounded leaves and
rather late season flowers are pure yellow and marked with a
deep crimson nectar guide.
80/063 (litiense) MIN: RKB (0)
528sd1995 RSBG ((10?\R2\4). Grown from seed collected wild in
529sd1995 CV#:RSBG ('10\R2\4). Grown from seed collected wild
in SE Tibet.
535sd95 RSBG ((10?\R2\4). Grown from seed collected wild in
SE Tibet from a plant with no blotch.
107sd1998 (Litiense Group) RSBG ('10\R2\4). Grown from seed
collected wild (DWD#206) at 12,900 ft. in NW Yunnan, China
148sd2000 wardii var. wardii CER#9905:RSBG (-10\R2\4). Beautiful yellow
saucer-shaped flowers in mid to late spring, often with a reddish
blotch. Rounded and smooth leaves on a rounded shrub. Grown from
seed collected by Garratt Richardson at 13,125 ft. in the Tsari
region of SE Tibet. Can be susceptible to powdery mildew.
Compact evergreen shrubs with distinct ovate-lanceolate foliage, dark
and shiny green on the upper surface. The lower surface has a reddish
brown indumentum which is nicely displayed due to the rather upright
position in which the current years growth is poised. The flowers
(mid-spring) are typically yellow to whitish (pink in the Rhododactylum
Group) with reddish spots. An attractive plant which is quite different
in appearance from the other members of subsection Taliensia. It is also
easier to cultivate than most other members of this group. Native to
forests in C Sichuan, China where it is found from 7,500 to 12,000 ft
65/258 Stronachullin ('10\R1\3). Pale yellow flowers.
65/303 RBGE ((5). Flowers white, lightly blushed rose with a few
74/036 (syn. wasonii var.rhododactylum) W 1876: WGP (0). White flowers.
76/267 WGP (0).
82/181 T Jorgensen (0).(Rhododactylum Group) Pink flowered form.
83/108 (syn. wasonii var. rhodoactylum) REU: ADM (0).
websteranum var. websteranum
Upright, branched shrubs to 5 ft. Flowers (April) are pale
purple. Native to heath and moorlands at 10,000 to 16,000 ft.
65/462 WIS (0). Vigorous dwarf with lavender flowers.
Shrubs, 5 to 25 ft. Flowers (March) are lilac to clear orchid-
purple to white and very fragrant. One of the least hardy of
this section, but unusually lovely flowers. Found at forest
margins and steep slopes at 2,500 ft. China.
65/462 Wisley (0). Tiny, narrow leaves and lavender flowers
on a vigorous dwarf.
Large deciduous shrubs or small trees with smooth reddish branches.
The rhombic (diamond-shaped) leaves are arranged in whorls of three
at the ends of the branches and are covered with short brownish hairs.
The openly funnel bell-shaped flowers (mid-spring to early summer)
are salmon-pink to brick red, usually with spots. The unusually colored
flowers and attractive foliage make this seldom-seen azalea a true
collector's item. Quite tolerant of heat. Native to S Japan and
Cheju Island, Korea.
73/298 USDA 274839-USDA (10?\R1\4).). Form with light orange-red
flowers in May. Yellow to red autumn color.
81/071 USNA ('10'\R1\4).
81/073 USNA ('10'\R1\4). I have not recorded flower data for
either of these clones.
Shrubs, 7 to 20 ft. Flowers (April) are pale to lemon-yellow with
brown or purple spots. Common above tree line where it is found
among scrub and on ridges at 11,000 to 15,000 ft. Himalayas
75/210 PTG (-5)
Low and densely-branched, mounding evergreen shrubs with distinct smooth
orbicular leaves. The pink to rose flowers appear as delicate bells
hanging from the branch tips in mid-spring. The new growth is usually a
deep reddish brown. An easily grown and popular species often used in
hybridizing. Native to a limited mountainous area in C Sichuan, China
where it grows on high cliffs from 8,000 to 10,000 ft.
66/606 CAE (-5). Form with delicate pink bells in early spring.
73/301 Greig: WW (-5). Clone with small, flat, round leaves
and light pink, cup shaped flowers/
73/302 AEK (-5). Rose flowers.
74/113 FR (-5).
75/277 GRE: UBCP (-5). Clone of typical leaves and open cup-
shaped pale rose flowers.
75/307 BAR: CHP (5\R1\2). Low mounding form creates a striking
focal point as plants mature in your garden. Delicate pink
80/004 FOX: ARD (-5)
80/055 Borde Hill (-5). Tight compact spreading shrub, up to
4" in 10 years.
Large rounded evergreen shrubs with distinctive, beautiful foliage.
The dark glossy green leaves have deeply impressed veins on the upper
surface while the underside has a thick pale to reddish brown indumentum.
The bell-shaped flowers (mid-spring) are white to pink with red flecks
and a crimson blotch. An easily grown and superb foliage plant. Native
to W Sichuan, China where it occurs in forests and on rocky slopes and
cliffs from 8,000 to 11,000 ft.
75/017 HIL (-5). White flowers from pink buds.
1975/088 Exbury ('5\R1\4). White flushed rose flowers with crimson
flecks on this 1957 Award of Merit form.
75/326 GRE: CHP (-5)
76/116 J. Caperci (-5).
311sd1993 SB#9215:RSBG ('5\R1\4). Grown from seed collected wild by
Warren Berg in Sichuan. Very nice foliage on these seedlings.
Shrubs to 7 ft. rarely epiphytic on tree trunks. Tubular, nodding
flowers (variable flowering time) are bright to deep red or
scarlet. Leaves, ovate to ovate-elliptic, are densely set along
the branches. Found mostly in open mossy forest or among grasses
on the margins of forests, more rarely in grassland above the
timberline at 10,5000 to 12,100 ft. Papua, New Guinea.
84/162 FM (+32). Propagated from a plant collected on Mt.
Giluwe, Papua New Guinea.
Relatively small-growing evergreen shrubs with smooth and peeling
reddish brown bark. The elliptic gray-green leaves are silvery brown
on the underside. The narrowly bell-shaped flowers are deep to pale
yellow and borne in profusion over a long period in late spring. A
very attractive plant with fine yellow flowers. Requires excellent
drainage. Great in a container if pinched a bit as a small plant.
Native to N Burma, SE Tibet and adjacent W Yunnan, China where it
occurs from 5,000 to 13,000 ft. on cliffs, rocks and in forests.
66/677 R.15 - WW (+15). A compact and hardier clone with
bright yellow funnel shaped flowers.
77/666 'Yellow Garland' F#21707:Windsor (+10\R1\3). Deep yellow
flowers on this Award of Merit form.
362sd1998 CCHH#8070:RSBG (+10\R1\3). Grown from my collection
of seed at 6,550 ft. in the Biluoxue Shan of W Yunnan, China.
1999/282 xanthostephanum R#15:Doleshy (+10\R1\3). Smooth and peeling
shiny red-brown bark with gray-green leaves and deep yellow bells
in late spring on this excellent form. Great in a container with
A relatively newly scientifically described species (1987), these
represent the first introduction into cultivation. This is a
relative of the familiar R. davidsonianum with similar white
to pink flowers in mid-spring. Should be as successful in
cultivation as its many popular relatives in Subsection
"yakushimanum" (see degronianum ssp. yakushimanum)
Dense mounding shrubs, 3 to 8 ft. Light pink or rose buds opening
to white or white flushed pink flowers (May) with or without
faint pink flecks. Dwarf to semi-dwarf habit, foliage with thick
white to fulvous indumentum, and exceptional flowers make this
one of the most popular species. Native solely to Yaku Island in
conifer forests and on exposed mountain slopes from 1,500 to
6,500 ft. Japan
64/012 'Koichiro Wada' WGP-ACL. An award form similar to the
Exbury form, flowers deep pink in bud, opening white. FCC 1947
73/308 RCH (-15). A very dwarf form.
73/310 EXB-PHB (-15). Form with apple blossom pink flowers.
75/184 'Yaku Angel' CS (-15). A more vigorous form with
larger trusses of white flowers.
75/260 (75/241) 'Exbury Form' EXB: FR (-15). Perfection of
dome shaped habit, deep green, heavily indumented foliage and
apple blossom pink flowers.
77/649 'Pink Parasol' D. Leach (-15). A possible hybrid with
large leaves and deeper pink flowers than average.
82/073 'Baron Lionel' EXB: UBC (-15).
83/100 ADM (-15). A dwarf form with pale rose flowers.
yedoense var. poukhanense
Semi-deciduous shrubs to 5 ft. Flowers (April-May) are rose to
pale lilac and slightly fragrant. One of the hardiest azaleas and
much used in hybridizing. Has relatively large flowers that
appear on young plants. Found in large masses on open grassy
slopes from sea level to 5,000 ft. Korea.
78/020 'Eizanko' Suzuki - WEB (0).
78/021 'Shizanko' Suzuki:Berg ('15\R1\3). Bright magenta flowers
with darker magenta flecks.
78/024 Suzuki:Berg ('15\R1\3). Dark rose-purple flowers with
90/014 Yoder('15\R1\3). I have not recorded flower data for this clone.
A new and very exciting species in cultivation. This is, in general
appearance, a dwarf and compact version of the well-known species
orbiculare and has similar rounded leaves. The leaves are much
thicker and more firm in texture than that familiar species and
the petiole is quite short and wide. Bright glaucous blue-green
new growth - a really amazing foliage plant. Funnel-bell-shaped
pink flowers in early summer - quite a late-blooming species
and flowering from a very young age. Seems to be hardy (surviving
in sheltered areas on the east coast!) and best in very light
shade or morning sun. You will love this plant. (0?\R1\3) RSBG
Rounded compact shrubs, 1 to 4 ft. Wide, funnel-shaped flowers
(April-May) are deep purple, blue-purple, or purple-red, rarely
white, and produced in great abundance on this vigorous species.
Occurs on alpine meadows, stony moorlands, cliffs and rocky areas
from 11,000 to 14,000 ft. China (SW Sichuan, N Yunnan).
83/137 F 16282: RBG (0).
Large, vigorously upright-growing evergreen to sometimes deciduous
shrubs. The attractive, widely funnel-shaped flowers are sometimes
fragrant and extremely variable in color. They are borne profusely
every year and range from white to pink or lavender, typically with
red, green or yellow spots and/or a blotch. Easily grown, floriferous
and quite tolerant of most garden conditions including drought once
established. Very common and widespread in the wild where it is found
from 3,000 to 14,000 ft. in a wide range of habitats. Native to China
(N Yunnan, SW Sichuan, Guizhou), Burma and SE Tibet.
70/333 FOR (0). Form with white flowers accented with orange
80/033 EM (0). Form with light pink flowers.
83/111 ADM (0). Form with lavender-pink flowers.
511sd1996 SEH#182:RSBG (0\R1\6). Grown from my collection of seed
at 9,200 ft. in NE Yunnan, China.
Shrubs, 6 to 26 ft. Flowers (April-May) white, white flushed pink
of lavender. A distinct species with a rather southerly and low
altitude distribution. Found in scrub, thickets and forest
margins at 5,800 to 9,800 ft. N Burma, China
77/680 CRA (+10). Highly praised form with large mauve-pink
Tropical shrubs or small trees to 20 ft. Flowers (flowering time
varies) are yellow to orange or reddish-salmon and can have
orange-red lobes. Widely used in hybridizing as a source of vivid
color. Often found as an epiphyte in rain forest, open areas, or
hanging over precipices and streams from sea level to 6,500 ft.
Indonesia, Papua New Guinea, Moluccas
80/150 BOS (+32\R1\?). Long funnel-shaped flowers, yellow with
83/061 SCHI (+32\R1\?). This clone collected wild on Koebre
Ridge, New Guinea at 7,500 ft. Saffron-yellow tubes and orange
flushed vermilion lobes.
83/071 PS (+32\R1\?). Collected wild in New Guinea.
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Key to source abbreviations
AC Alan Clark
ACUB Berry Botanic Garden
ARS American Rhododendron Society
CC Cox & Cox
CCH Chamberlain, Cox & Hutchison
CCHH Chamberlain, Cox, Hootman, Hutchison
C&H Cox & Hutchison
CHC Cox, Hootman & Cox
CNW Clark, Nielsen, Wilson
CV Cox & Vergara
DJHC Daniel Hinkley
EGM Ted Millais
F George Forrest
HTS Henry T. Skinner
JN Jens Nielsen
KR Keith Rushforth
KW Frank Kingdon Ward
K&Y Y. Kurashige & T. Yukawa
LS&T Ludlow, Sherriff & Taylor
PW Peter Wharton
R Joseph Rock
RBGE Royal Botanic Garden Edinburgh
RBGK Royal Botanic Garden Kew
RSBG Rhododendron Species Botanical Garden
S Akagi Nature Park
SEH Steven E. Hootman
UBCBG University of British Columbia Bot. Garden
USDA U.S. Dept. of Agriculture
USNA U.S. National Arboretum
W Ernest H. Wilson
YK Y. Kurashige, Akagi Nature Park