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Rhododendron gratum R. Til G R.

Rhododendron gratum

 R. rex ssp. gratum i Købh. Bot. Have, Foto: Hans Eiberg
R. gratum (en form af R. basilicum) i Købh. Bot. Have, Foto: Hans Eiberg

 R. gratum i Købh. Bot. Have. Foto: Hans Eiberg
R. gratum i Købh. Bot. Have, Foto: Hans Eiberg

 R. gratum i Købh. Bot. Have. Foto: Ole Jonny Larsen
R. gratum i Købh. Bot. Have, Foto: Ole Jonny Larsen

 R. gratum i Købh. Bot. Have. Foto: Ole Jonny Larsen
R. gratum i Købh. Bot. Have, Foto: Ole Jonny Larsen

R. gratum (form af R. basilicum ?) Tidligere R. rex ssp. gratum

R. gratum (tidligere R. rex ssp. gratum) (Falconera) er tæt beslægtet med R. basilicum (måske samme art som denne). Et kendetegn er at bladstilken er svagt vinget, men noget fladtrykt, medens R. rex er rund. R. basilicum har en mere vinget bladstilk
Hans Eiberg

D. Genbank
Herbarium
R. gratum in RBGE



Flora of China
:
Leaf blade usually elliptic; abaxial surface indumentum usually discontinuous, transparent or translucent, sometimes quickly lost. Corolla without color flecks. Fl. Apr–May.Rhododendron thickets; ca. 3200 m. W Yunnan.
Field observations at the type locality suggest that subsp. gratum is a form of Rhododendron basilicum with only slightly winged petioles; this fits reasonably well with the distribution of the latter species.

Comments:
The taxon was named from the Ziben shan just north of Coajian. David Chamberlain treated it as a synonym of R. basilicum and thinks there is a hybrid swarm at the old tin mine site. Then the Chinese made it a form of rex. More credible, I suspect, is John McQuire's recent observation on a couple of Alan Clark numbers that it seems closer to R. semnoides. I've been to the site twice, in 1993 and 2002, but have killed off my plants. Tom Hudson has it from his first two visits (1993 and a year or two later, he didn't collect any more in 2002) and I have one of Alan Clark's numbers, whereas John has two (3009 + 3014). Looking at the hairs on one of Tom's plants, they are the open bowl shape for R. basilicum, but strongly fimbriated. Also in the same "pie" are the plants Tom and I collected from Yongdeshan in 2002. Tom flowered one and it had an enormous yellow truss, top quality. Cup shaped hairs, but not R. basilicum nor R. rex in my book. Keith Rushforth