actinomorphic: Radially symmetrical; divisible into equal halves by two or more planes drawn through the middle.
acuminate: Tapering gradually to a point and forming more or less concave sides.
acute: Tapering to a sharp, pointed apex with more or less straight sides; broader than acuminate.
adpressed: Of parts that are lying close together, but are not fused.
alternate: (of leaves) Arranged with one leaf per node along the stem. (compare opposite)
anther: The pollen-producing, apical part of the stamen (sometimes sessile; without a filament).
apex (pl. apices; adj. apical): The point farthest from the point of attachment.
appressed: Pressed close or flat.
auct.: Denotes a name applied by authors to the wrong entity.
auriculate: With ear-shaped lobes (as the base of leaves).
awl-shaped: Narrowly triangular and small.
awn: A narrow, bristle-like organ.
axil (adj. axillary): The upper angle between an axis and a lateral organ (as between a stem and a leaf).
axis: A straight line through the center of a structure around which the parts are usually symmetrically arranged (geom.); the main stem (bot.).
topbasal: At or pertaining to the point of attachment.
basifixed: Of an anther: attached to the filament at its base.
bearded: Bearing tufts of long hairs.
bifid: Two-cleft or two-lobed.
bilabiate: Two-lipped.
bisexual flower: A flower with both stamens and pistils.
bract: A modified leaf near a flower or inflorescence, often reduced.
bracteole: A secondary bract often borne on a petiole.
bristle: A stiff hair or hair-like structure.
calyx: The outer whorl of the perianth; all the sepals of a flower.
campanulate: (of a corolla, perianth or calyx tube) Bell-shaped; with a broad base, sides curving to a flared rim.
capitulum: see head.
carpellate: Of flowers bearing carpels (female reproductive parts) and lacking stamens.
caudate: Tapering to a long, tail-like appendage.
chaffy: With thin, dry, membranous scales or bracts.
ciliate: With a marginal fringe of hairs.
claw: The narrowed base of some petals. (compare limb)
compound: With two or more like parts, as in a compound inflorescence or compound leaf.
compound leaf: A leaf divided into two or more leaflets.
connate: Union of like parts (fusion).
corolla: The inner whorl(s) of the perianth; all the petals of a flower.
corona: An appendage between the corolla and the stamens.
corymb: A flat-topped or round-topped racemose inflorescence.
corymbose: (of an inflorescence) Corymb-like or having flowers borne in corymbs.
cultivar: A horticultural race or variety of a plant that has originated and persisted only under cultivation.
cyathium: A specialized inflorescence type occurring in the Euphorbiaceae consisting of unisexual flowers enclosed in a cup-shaped involucre.
cyme: A determinate, usually flat-topped or convex inflorescence in which the terminal flower blooms earliest.
topdeclinate: Curved downward.
decurrent: (of a leaf) Extending downward along the stem from the point of insertion.
decussate: (of opposite leaves) Arranged on the stem in pairs, with alternating pairs at right angles.
deflexed: Bent abruptly downward.
determinate: (of an inflorescence) With the terminal or central flower opening first, so that the main axis does not elongate further.
disbudded: (of an inflorescence) Having all subtending axillary buds removed, leaving only a terminal bud, so that only one large flower (or head) develops.
disc floret: A flower with an actinomorphic, sympetalous corolla on heads in the Asteraceae.
discoid: With disc flowers, as in Asteraceae heads.
dissected: (of leaves) Cut or lobed in any way, but not compound.
distichous: (of leaves or flowers) Distinctly arranged in two ranks along an axis; leaves may be opposite or alternate.
dorsifixed: (of an anther) Attached to the filament at its back.
double: (of a flower or head) With more than the normal number, or extra whorls, of petals, tepals, perianth segments, or petaloid sepals; in the Asteraceae, heads with more than the normal number of ray florets.
topequal: Of plant parts being compared, where the parts are similar in length or terminate at the same point.
elliptic: Oval.
emarginate: With a shallow notch at apex.
ensiform: Sword-shaped (usually to describe larger parts than awl-shaped.
entire: Having a continuous margin that is not toothed or lobed.
epigynous: With stamens, petals and sepals (or perianth whorls) attached at the top of the ovary.
exserted: Projecting or extending beyond surrounding parts (as, e.g. stamens projecting from a perianth tube).
filament: The stalk of the stamen bearing the anther.
filiform: Thread-like; long and thin.
floret: One of the small individual flowers within a dense cluster of flowers.
flower: The reproductive structure of the angiosperms. A complete flower consists of stamens, pistils, and a perianth of calyx and corolla (or tepals or perianth parts).
funnelform: (of a corolla, perianth or calyx tube) Funnel-shaped; flaring with straight sides from a narrow base.
glabrous: Without hairs.
globose: Spherical.
gynostegium: The specialized structure formed from the adnation of the stamens and the stigmas in the Asclepiadaceae.
tophead: A dense, clustered inflorescence of sessile or subsessile flowers on a very short axis.
hort.: 1) The misapplication of a name by gardeners that is actually a validly published name for a different entity; or 2) to denote a name of horticultural origin published in writings of confused authorship or of no standing as a valid publication.
hybrid: A plant produced from a cross between genetically distinct parents or different species or genera.
hypanthium: The cup-shaped structure formed from the fusion of the basal parts of the calyx, corolla, and stamens, on the rim of which these parts arise.
imbricate: Overlapping in a regular pattern, like shingles on a roof.
imperfect: Of a flower, lacking either stamens or pistil(s); unisexual.
indeterminate: (of an inflorescence) With lower or outer flowers opening first, so that the main axis continues elongating.
inferior ovary: An ovary that lies beneath the point of attachment of the other floral whorls; can also be interpreted as an ovary that is fused to a hypanthium. (compare superior ovary)
inflexed: Curved or bent inwards toward the axis.
inflorescence: The arrangement of flowers on the floral axis.
involucel: A secondary involucre, as in the Apiaceae.
involucre: A whorl or whorls of bracts subtending a flower or inflorescence.
irregular: Not divisible into equal halves.
keel: A prominent longitudinal ridge.
keeled: Folded longitudinally, with or without a longitudinal midrib.
toplabellum: A lip.
lanceolate: Lance-shaped; widest point below the middle, tapering to the apex. (compare oblanceolate)
lateral: Of, at, or from the side.
leaflet: One of the leaf-like units of a compound leaf.
lenticular: Lentil-shaped; biconvex.
ligulate head: In the Asteraceae, a head bearing only ray florets.
ligule: The strap-shaped corolla limb of the ray florets in the Asteraceae.
limb: Expanded part of a petal, tepal or leaf or of a corolla or perianth tube. (compare claw)
lobe: (of a corolla, perianth, or calyx tube) One segment of the limb of the tube; the expanded, unfused part of a petal, tepal, sepal, or perianth segment.
locule: A cavity or compartment in an organ, as the pollen-producing compartment of an anther.
merous: Suffix indicating the number of parts in a flower, e.g., 5-merous = 5 corolla lobes, 5 carpels, etc.
midrib: The main or central vein, line or rib in a leaf or perianth segment.
monoecious: Having separate male and female flowers on the same individual plant.
ms: Manuscript; not a published name.
mucronulate: Diminutive of mucronate (terminating with a short, sharp, abrupt tip).
topnode: The place on a stem where a leaf or leaves originate; or on an axis or other structure where organs arise.
non: Latin for 'not'. Used to differentiate between various applications of a name to different plant entities by different authors.
oblanceolate: Lance-shaped, with attachment at or near the narrow end. (compare lanceolate)
oblong: Two to four times longer than wide, with parallel sides.
opposite: (of leaves or other structures) Two borne at the same point on opposite sides of an axis. (compare alternate)
orbicular: Round in outline.
ovate: Egg-shaped in outline, generally with attachment at or near the broad end. (compare ovoid)
ovoid: Egg-shaped in three dimensions. (compare ovate)
palmate: (of leaves or venation) With lobes, leaflets, divisions or veins originating from the same point. (compare pinnate)
panicle: An indeterminate, branched (often much-branched) inflorescence; the ultimate units may be of a different inflorescence type.
paniculate: In the form of a panicle; bearing panicles.
pappus: The modified calyx in the Asteraceae, composed of hairs, bristles, awns, or scales.
pedicel: The stalk of a single flower in an inflorescence.
pedicellate: Borne on a pedicel.
peduncle: The stalk of a flower cluster or inflorescence.
pendent: Hanging downwards.
perfect: (of a flower) With both functional male and female reproductive organs (stamens and pistils); bisexual.
perfoliate: (of a leaf) With the margin completely surrounding the stem, so that the stem appears to pass through the leaf.
perianth: Collective term for the calyx and corolla of a flower; also used specifically for whorl(s) that cannot be differentiated into calyx and corolla.
perianth part; perianth segment: One unit of the perianth.
petal: One segment of the corolla, used when the petal segments are completely separate.
petiole: The stalk of a leaf.
petiolule: The stalk of a leaflet in a compound leaf.
phyllary: An involucral bract in the Asteraceae.
phyllotaxy: The arrangement of leaves on the stem.
picotee: Term to describe a narrow band of color at the distal edge of a petal, tepal, or perianth segment.
pinnate: (of leaves or venation) With more than three leaflets, lobes or veins arranged in two rows along an axis. (compare palmate)
pinnatifid: (of leaves) Deeply pinnately lobed half way or more, but not reaching, the midrib.
pinnatisect: Pinnately cut or lobed to the midrib.
pistil: The female reproductive organ, usually consisting of an ovary, a style, and a stigma, formed from one or more carpels.
pollen presenter: A term for the style-end in some flowers, in which pollen is deposited on the style-end by anthers in the same flower; the pollen is collected by pollinators from the style-end rather than the anthers directly.
pollinium: A mass of waxy, coherent pollen grains transported as a unit in the Asclepiadaceae or Orchidaceae.
poricidal: (of anthers) Having pores through which pollen escapes.
quilled: (of petals or ray floret limbs) Nearly terete, hollow, or involute; quill-like; (of cultivars) with quilled or petals or limbs.
topraceme: An indeterminate, unbranched inflorescence having pedicelled flowers on a usually elongated axis.
racemose: Raceme-like or bearing racemes.
radiate head: In the Asteraceae, a head consisting of both ray florets and disc florets.
ray: One of the branches of an umbel.
ray floret: A zygomorphic flower with a strap shaped corolla on heads in the Asteraceae.
receptacle: The enlarged or elongated apex of the pedicel on which the flower parts are borne; in the Asteraceae the enlarged apex of the peduncle on which the florets in a head are borne.
recurved: Curved downward or backward.
reflexed: Abruptly curved or bent downward.
regular: see actinomorphic.
revolute: With margins rolled downward, or to the lower side.
rotate: Wheel-shaped, of a corolla or perianth with a short tube and spreading, horizontal limb.
tops.l.: see sensu lato.
salverform: (of a corolla or perianth) With a long, slender tube and an abruptly expanded, flat limb.
scale: Short, thin, flat bracts or hairs.
scape: A leafless peduncle arising from the ground, and bearing flower(s) or an inflorescence.
scarious: Dry, thin, membranous, non-green, more or less translucent.
semi-double: Partly or not fully double.
sensu lato: Latin for "in the broad sense".
sepal: A member of the outer envelope of a flower (calyx).
sessile: Attached without a stalk.
simple leaf: Not compound; not divided into leaflets.
single: (of a flower or head) Not bred to be double; having the normal number or whorls of petals, perianth parts, tepals, or, in the Asteraceae, ray florets.
sinus: The indentation or space between two units, as the lobes on a leaf or petal.
spadix: A spike with a fleshy axis, and small, densely crowded flowers.
spathe: A large, sometimes colored bract enclosing or subtending an inflorescence.
spatulate: Like a spatula; rounded at the apex, with base long and tapered.
spike: An indeterminate, unbranching inflorescence of sessile flowers or flower clusters on a usually elongated axis.
spikelet: A small spike.
spray: (of an inflorescence) With the apical bud removed, so that all axillary flowers (or heads) develop; a full inflorescence with numerous flowers open at the same time.
spur: A sac-like projection or extension of a petal or sepal.
stamen: The male reproductive organ, consisting of a pollen-bearing anther, and a filament.
staminate: Bearing stamens but not pistils.
staminode: A sterile stamen, often modified in appearance and with an empty, often much reduced anther that does not produce pollen.
sterile: Infertile, as a stamen without an anther or a flower without a pistil.
stigma: The apical, pollen-receptive part of the pistil.
style: In a flower, the narrow and elongated part of the pistil between the stigma and the ovary.
stylopodium: A disc-like enlargement of the style bases present in some Apiaceae.
sub: A prefix meaning slightly, somewhat, or nearly (used with a descriptive term), or below (used with an anatomical term).
subtend: Situated directly beneath an organ, as bracts beneath an inflorescence.
superior ovary: Situated above the point of attachment of the other floral whorls. (compare inferior ovary)
sympetalous: With the petals united, sometimes only at the base.
synsepalous: With the sepals united, sometimes only at the base.
tepal: A member of the perianth, when it is in two whorls that are alike in size, color and texture, and cannot be differentiated into a calyx and corolla. Used primarily for monocot flowers.
ternate: In threes.
throat: The orifice of a corolla, calyx or perianth tube, or the region between the tube and the limb.
toothed: Bearing a margin of small projections alternating with indentations (general term).
trigonous: Three-angled.
tubular: (of a corolla, perianth or calyx tube) Tube-shaped, cylindrical; narrow and elongate with more or less straight sides.
turbinate: Top-shaped.
topumbel: A flat to convex inflorescence in which the flower pedicels (called rays) all arise from the same point.
unisexual flower: A flower with either stamens or pistils but not both.
urceolate: (of a corolla, perianth or calyx tube) Urn-shaped; more or less ovoid or globose, and constricted near the rim.
var.: Variety; a taxonomic category below the subspecies level.
ventral: Of the inner or axis side of an organ.
whorl: Three or more similar organs arranged in a circle at the same point around an axis.
zygomorphic: Bilaterally symmetrical; divisible into two equal halves along only one plane.