GLOSSARY OF TAXONOMIC TERMS

From: Amer Taxonom Society?


                       GLOSSARY OF TAXONOMIC TERMS 
          Commonly Employed in the Identification of Woody Plants


Achene -       A dry indehiscent one-seeded fruit. Ex: fr. of
               members of the Compositae.

Acuminate -    Having an apex whose sides are gradually
               concave and tapering to a point.

Acute -        Having an apex whose sides are straight and taper
               to a point.

Adventitious - Arising from an unusual or irregular position.

Aggregate flower -  A flower heaped or crowded into a dense
               cluster.

Aggregate fruit -   One formed by the coherence or the connation
               of pistils that were distinct in the flower
               (as in Rubus) when the pistils of separate
               flowers (as in mulberry) make up the fr. it is
               designated as a multiple fruit.

Alternate -    An arrangement of leaves or other parts not
               opposite or whorled; parts situated one at a
               node, as leaves on a stem: like parts
               succeeding each other singly with a common
               structure.

Ament -        See catkin.

Apetalous -    Without petals. Ex: fls. of grasses.

Apex -         The tip or terminal end.

Apical -       Describes the apex or tip.

Apiculate -    Ending abruptly in a short pointed tip.

Appressed -    Pressed close to the stem, not spreading.

Auriculate -   Bearing ear-like appendages, as the
               projections of some leaf and petal bases.

Berry -        A fleshy indehiscent pulpy multi-seeded fr.
               resulting from a single pistil. Ex: tomato.

Bipinnate -    Twice pinnate.

Bloom -        A waxy coating found on stems, leaves, flowers and
               fruits, usually of a grayish cast and easily
               removed.

Boss -         A raised usually pointed projection.

Bract -        A much-reduced lf., often scale-like and usually
               associated with a fl. or infl.

Broad-elliptic - Wider than elliptic.

Broad-ovate -  Wider than ovate.

Bud scale -    A modified leaf or stipule (there may be one,
               a few, or many) protective of the embryonic
               tissue of the bud.

Bud scale scar -    The mark left by the sloughing off of the bud
               scale.

Bundle scar -  Seen in the leaf scar, the broken ends of the
               woody vascular strands that connected the leaf
               and the stem.

Calyx -        The outer set of perianth segments or floral
               envelope of a flower, usually green in color and
               smaller than the inner set.

Capsule -      A dry dehiscent fruit produced from a compound
               pistil. Ex: fruit of a tobacco, Catalpa, Dianthus.

Catkin -       A spike-like infl. comprised of scaly bracts
               subtending unisexual fls., often somewhat flexuous
               and pendulous but not necessarily so. Ex: infl. of
               willows (Salix) and poplars (Populus).

Chambered -    Of pith, divided into empty horizontal
               chambers by cross partitions.

Ciliate -      Marginally fringed with hairs, often minutely so
               and then termed "ciliolate."

Clone -        A group of plants derived vegetatively from one
               parent plant, identical to each other and to the
               parent.

Coarse texture -  Consisting of large or rough parts.

Compound leaf - A leaf of two or more leaflets.

Cone -         A coniferous fruit, having a number of woody,
               leathery, or fleshy scales, each bearing one or
               more seeds, and attached to a central axis.

Conical -      Cone shaped, as the young form of many spruces.

Coniferous -   Cone, bearing.

Cordate -      Heart-shaped, with a sinus and rounded lobes.

Corymb -       A more or less flat-topped indeterminate infl.
               whose outer fls. open first. Ex: Viburnum, some
               verbenas.

Crenate -      Rounded teeth on mgn. Ex: Ivs. of some Coleus.

Crenulate -    Having very small rounded teeth.

Cultivar -     A cultivated variety.

Cuneate -      Wedge-shaped with essentially straight sides, the
               structure attached at the narrow end.

Cyme -         A more or less flat-topped determinate infl. whose
               outer fls. open last. Ex: elderberry (Sambucus).

Dehiscent -    Splitting open.  The term is commonly applied
               to anthers or seed pods.

Dentate -      Having marginal teeth whose apices are
               perpendicular to the margin and do not point
               forward.

Dicot -        Angiospermous plant having two cotyledons.

Dimorphic -    Having two forms.

Dioecious -    Having unisexual fls., each sex confined to a
               separate plant, said of species.

Double serrate - Serrations bearing minute teeth on margins.


Drupe -        A fleshy indehiscent fr. whose seed is enclosed in
               a stony endorcarp. Ex: date, cherry.

Ellipsoid -    Three dimensional shape of ellipse, football
                    shaped.

Elliptic-oblong -   A shape between the two forms.

Elliptical -   Having the outline of an ellipse, broadest at
               middle and narrower at each end.

Emariginate -  With a shallow notch at the apex.

Endocarp -     The inner layer of the pericarp.

Entire -       Having a margin without teeth or crenations.

Even-pinnate - Results in a lack of the terminal leaflet, since
               each one is paired.

Exfoliate -    To peel off in shreds or thin layers, as bark
               from a tree.

Falcate -      Sickle-shaped.

Fascicle -     A close cluster. Ex: lvs. of white pine.

Filiform -     Long and very slender; thread-like.

Fine texture - Consisting of small rather delicate parts.

Flaking -      Shreddy, with shorter fragments.

Follicle -     A dry dehiscent fruit opening only along one
               suture and the product of a single carpel
               (simple ovary). Ex: peony, columbine,
               milkweed.

Fruit -        Technically a ripened ovary with its adnate parts,
               the seed-containing unit characteristic of all
               Angiosperms.

Genus -        A group of species possessing fundamental traits in
               common but differing in other lesser
               characteristics.

Glabrous -     Not hairy. Note: a glabrous surface need not
               be smooth, for it may be bullate or rugose.

Glandular -    Bearing glands.

Glaucescent -  Slightly glaucous.

Glaucous -     Covered with a waxy bloom or whitish material
               that rubs off readily. Ex: the bloom on many
               sorts of grape.

Globose -      Having a round or spherical shape.

Grooved -      Marked with long narrow furrows or channels.

Hairy -        Pubescent with longer hairs.

Hispid -       With stiff or bristly hairs.

Hirsute -      Pubescent with coarse or stiff hairs.

Imbricated -   Overlapping, as shingles on a roof.

Imperfect -    A flower that lacks either stamens or pistils.

Incised -      Cut by sharp and irregular incisions more or less
               deeply, but intermediate between toothed and lobed.

Indehiscent -  Not opening regularly, as a capsule or anther.

Indumentum -   With a generally heavy covering of hair: a general
               term without precise connotation.

Inferior -     Beneath, below; said of an ovary when situated
               below the apparent point of attachment of
               stamens and perianth.

Involucre -    One or more whorls or series of small lvs. or
               bracts that are close underneath a fl. or
               infl.

Juvenile -     An early phase of plant growth, usually
               characterized by non-flowering, vigorous
               increase in size, and often thorniness.

Lanceolate -   Much longer than wide, broadest below the
               middle and tapering to the apex.

Lateral bud -  A bud borne in the axil of a previous season's
               leaf.

Latex -        Milky sap.

Leaf scar -    The mark remaining after the leaf falls off a
               twig.

Lenticel -     A small corky spot on young bark made of
               loosely packed cells, providing gaseous
               exchange between the inner tissues and the
               atmosphere.

Linear -       Long and very narrow, as in blades of grass.

Lobe -         A projecting part or segment of an organ as in a
               lobed ovary or stigma; usually a division of a lf.,
               calyx, or petals cut to about the middle (i.e.
               midway between margin and midrib).

Margin -       The edge of a leaf.

Marginal -     Pertaining to the margin.

Mature -       A later phase of growth characterized by flowering,
               fruiting, and a reduced rate of size increase.

Milky sap -    Whitish in color, often thicker than water.

Monoecious -   A species with unisexual fls., having both
               sexes on the same plant. Ex: corn.

Mucro -        A short, sharp, abrupt tip.

Mucronate -    Abruptly terminated by a mucro.

Multiple buds - A terminal or lateral bud crowded by many
               accessory buds.

Naked bud -    One without scales.

Native -       Inherent and original to an area.

Needle -       The slender leaf of many conifers.

Nerve -        A slender rib or vein, especially unbranched.

Node -         A joint on a stem, represented by point of origin
               of a leaf or bud; sometimes represented by a
               swollen or constricted ring, or by a distinct leaf
               scar.

Nut -          A dry, indehiscent, 1-celled, 1-seeded fruit
               having a hard and bony mesocarp; the outermost
               endocarp may be fibrous or slightly fleshy.

Obscordate -   The apex being codate.

Oblanceolate - Inversely lanceolate.

Oblique -      Lop-sided, as one side of a leaf base larger, wider
               or more rounded than the other.

Oblong -       Longer than broad; rectangular; the sides nearly
               parallel.

Oblong -       Lanceolate: a shape in between the two forms.

Oblong-obovate -  A shape in between the two forms.

Obovate -      Inversely ovate, broadest above the middle.

Obovoid -      Three dimensional shape of obovate, pear shaped.

Obtuse -       Rounded, approaching the semi-circular.

Opposite -     Two at a node, as leaves.

Orbiculate -   Circular or disk-shaped. Ex: leaf of common
               nasturtium.

Oval -         Twice as long as broad, widest at the middle,
               both ends rounded.

Ovate-oblong - A combination of the two forms.

Palmate -      Digitate, radiating, fan-like from a common point,
               as leaflets of a palmately compound lf. or veins or
               palmately-veined lf.

Panicle -      An indeterminate infl. whose primary axis bears
               branches of pedicelled fls. (at least basally so);
               a branching raceme.

Peltate -      Having the petiole attached inside the margin, such
               a lf. is typically shield-shaped.

Pendulous -    More or less hanging or declined.

Pericarp -     A term used by some to designate a fruit;
               technically, the ovary wall.

Periderm -     A protective layer of corky cells.

Petiole -      Leaf-stalk.

Petiolule -    Leaflet-stalk.

Pilose -       Shaggy with soft hairs.

Pinna -        The lft. of a compound lf.; of ferns, the primary
               division attached to the main rachis; feather-like.

Pinnate -      Compounded with the lfts. or segments along each
               side of a common axis or rachis; feather-like.

Polygamous -   Bearing unisexual and bisexual flowers on the
               same plant.

Pome -         A type of fleshy fruit represented by the apple,
               pear and related genera, resulting from a compound
               ovary.

Prickle -      An excrescence of bark that is small, weak, and
               spine-like.

Pseudo-terminal bud -    Seemingly the terminal bud of a twig, but
                         actually the upper-most lateral bud with
                         its subtending lf. scar on one side and
                         the scar of the terminal bud often
                         visible on opposite side.

Pubescent -    Covered with short soft hairs; a general term.

Pyramidal -    Broadest at base, tapering apically; pyramid-
                    shaped.

Raceme -       A simple indeterminate inflorescence with
               pedicelled flowers.

Rachilla -     A diminutive or secondary axis; a branch of a
               rachis; the minute axis bearing the individual
               florets in grass and sedge spikelets; the
               secondary axes of decompound fern fronds.

Rachis -       Axis bearing leaflets or the primary axis of an
               infl.; the axis bearing pinnae of a fern frond.

Ranked -       Foliage is arranged in longitudinal planes around
               the stem.

Receptacle -   A torus; the distal end of a flower-bearing
               axis, usually more or less enlarged,
               flattened, or cup-like on which some or all of
               the flower parts are borne.  Ex: Compositae,
               Onagraceae.

Reflexed -     Bent abruptly backward or downward.

Reinform -     Kidney-shaped.

Resin duct -   A lengthwise or transverse canal carrying
               resins.

Resinous -     Secreting a viscid exudate.

Reticulate -   Like a net, the interstices closed.

Rhombic -      With four nearly equal sides, but unequal angles,
               diamond shaped.

Rugose -       Wrinkled, usually covered with wrinkles.

Samara -       A dry indehiscent fruit bearing a wing (the wing
               may be limb-like or envelop the seed and be wafer-
               like). Ex: maple, ash, Ptelea.

Scar -         The mark left from a former attachment.

Schizocarp -   A dry dehiscent fr. that splits into two
               halves. Ex: maple.

Serrate -      Saw-toothed, the teeth pointing forward.

Serrulate -    Minutely serrate.

Sessile -      Without a stalk.

Simple -       Said of a lf. when not compound, of an infl. when
               unbranched.

Sinuate -      With a strongly wavy margin.

Sinus -        The space between two lobes, segments, or
               divisions; as of Ivs. or perianth parts.

Solitary -     Occurring alone, not paired or clustered.

Spatulate -    Spoon-shaped.

Species -      A natural group of plants composed of similar
               individuals which can produce similar offspring;
               usually including several minor variations.

Spike -        A usually unbranched, elongated, simple,
               indeterminate infl. whose fls. are sessile; the
               fls. may be congested or remote.

Spikelet -     (1) a secondary spike; (2) one part of a
               compound infl. which of itself is spicate; (3)
               the floral unit, or ultimate cluster, of a
               grass infl. comprised of fls. and their
               subtending bracts.

Spine -        An excrescence of st., strong and sharp-pointed.
               Ex: spines of hawthorns.

Squarrose -    With branches spreading and recurved at the
               ends.

Stalked bud -  A bud whose outer scales are attached above
               the base of the bud axis.

Stellate -     Star-like; stellate hairs having radiating
               branches or are separate hairs aggregated in
               star-like clusters; hairs once or twice forked
               often are treated as stellate.

Stipel -       A stipule of a lft.

Stipule -      A basal appendage of a petiole, usually one at each
               side, often ear-like and sometimes caducous.

Striate -      With fine longitudinal lines, channels or ridges.

Strigose -     With sharp, stiff, straight and appressed
               hairs.

Strobilus -    A cone.

Subtend -      To stand immediately beneath.

Sympodial -    Continuing growth by the development of an
               axillary bud and not the terminal bud, season
               after season.

Tendril -      A modified stem or leaf, usually filiform, branched
               or simple, that twines about an object providing
               support.

Tepal -        A segment of perianth not differentiated into calyx
               or corolla. Ex: tulip, magnolia.

Terminal -     At the tip or distal end.

Ternate -      In threes.

Thorn -        A modified twig which has tiny leaf scars and buds;
               can be single or branched.

Tomentose -    Densely woolly, the hairs soft and matted.

Translucent -  Transmitting light but diffuse enough to
               distort images.

Trifoliate -   Three-leaved. Ex: Trillium.

Truncate -     As if cut off at right angles to the primary
               axis; a term applicable to bases or apices.

Umbel -        An indeterminate infl., usually but not necessarily
               flat-topped with the pedicels and peduncles (termed
               rays) arising from a common point, resembling the
               stays of an umbrella.

Umbo -         A conical projection arising from the surface.

Undulate -     Wavy, as a leaf margin.

Valvate -      (1) dehiscing by valves; (2) meeting by the edges
               without overlapping, as lvs. or petals in the bud.

Variegated -   Striped, margined or mottled with a color
               other than green, where green is normal.

Variety -      Subdivision of a species having a distinct though
               often inconspicuous difference, and breeding true
               to the difference.  More generally also refers to
               clones.

Vascular bundle -   A discrete group of conducting vessels.

Vascular bundle scar -   A minute spot within the leaf scar where
                         the vessels were positioned.

Velutinous -   Clothed with velvety indumentum comprised of
               erect straight dense moderately firm hairs.

Whorl -        Arrangement of three or more structures arising
               from a single node.

Woolly -       Having long, soft, more or less matted hairs; like
               wool.







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