umbel: an inflorescence (strictly an indeterminate one) in which all the flowers or flower-stalks arise from one point at the top of the peduncle. Fig. 17 J. adj. umbellate. cf. umbelliform.
umbellaster: a group of flowers (with the terminal bud ending in a flower) more or less arising from the one point, which may be derived from the condensation of a cyme, thyrsoid or panicle.
umbelliform (umbelloid): having the form of an umbel.
umbo: a conical projection arising from the surface. adj. umbonate.
unarmed: without spines or prickles.
uncinate: terminating in a hooked point.
undershrub: a small shrub, often partially herbaceous.
undulate: wavy, i.e. not flat. Fig. 8 J. cf. sinuate.
uni-: prefix: one: as in unisexual, of flowers with one sex.
uniflorescence: a unit inflorescence forming part of a conflorescence.
unifoliolate leaf (1-foliolate): a compound leaf reduced to a single leaflet, usually recognized by the articulated or jointed ‘petiole’, which is in fact a petiole plus a petiolule. Fig. 3 K.
unigeneric: of a family, having only one genus. cf. monotypic.
unilateral: of stamens, with anthers grouped to one side of the style.
unilocular: of an ovary, anther or fruit, having only one internal cavity.
unisexual: bearing only male or female reproductive organs, not both. cf. dioecious, monoecious.
unisporangiate (1-sporangiate): of an anther with only 1 pollen sac (area of pollen grain formation, microsporangium). cf. tetrasporangiate.
united: fused together.
unitubulose: organs with complete transverse septa and no obvious longitudinal septa (seen by splitting the organ). cf. pluritubulose.
utricle: a small bladder; a membranous bladder-like sac enclosing an ovary or fruit.
valvate: (1) opening by valves, e.g. loculicidal and septicidal capsules (Fig. 18 L & M), or of anther dehiscence (Fig. 20 D); (2) of floral parts, with the edges touching but not overlapping, Fig. 11 G. cf. imbricate.
valve: a lid or segment of an anther or capsule which opens or separates at dehiscence.
variety: a taxonomic category below that of species (and subspecies if both used); differentiates variable populations.
vascular plants: plants containing vascular tissue; the more highly evolved plants above mosses and liverworts.
vascular tissue: tissue specialized for the conduction of fluids.
vector: a carrier or transferring agent, e.g. transfer of pollen to the stigma by wind or insect etc.
vein: a strand of vascular tissue; the primary vein or midvein gives rise to secondary or lateral veins and in turn tertiary veins. See venation.
veinlet: a small vein; the ultimate (visible) division of a vein.
velamen: a water-retaining outer layer of aerial roots of some epiphytes, especially orchids.
velum: a membranous covering; a veil.
velvety: very densely covered with fine short soft erect hairs. Fig. 14 A.
venation: the arrangement of veins in a leaf. Fig. 9.
ventral (adaxial): towards the axis or stem. cf. dorsal.
vernation: the arrangement of the unexpanded leaves in a bud. Fig. 11. cf. aestivation.
verruculose: finely warty.
versatile: of an anther, attached near its midpoint to a filament so that the anther swings freely. Fig. 20 A. cf. basifixed, dorsifixed.
verticillate: in a whorl.
vesicle: a bladder-like sac or cavity filled with gas or liquid. e.g. of hairs that are inflated and bladder-like; vesicular hairs often collapse and form a silvery layer on the surface of the organ on which they are formed. Fig. 15 D. adj. vesicular.
vessel: a capillary tube formed from a series of open-ended cells in the water-conducting tissue of a plant.
vestigial: reduced from the ancestral condition and no longer functional. cf. rudimentary, obsolete.
vicariant: of species, one of a closely related group with a replacement pattern in different areas of distribution; e.g. see Casuarina obesa and C. glauca.
villous: covered with long shaggy hairs, not matted. Fig. 14 G.
virgate: with many long slender ascending almost parallel branches. Fig. 1 C.
viscidium: of orchids, a viscid (sticky) part of the rostellum which is clearly defined and removed with the pollinia to an insect or other pollination vector.
viscous: of a liquid, not pouring freely; having the consistency of syrup or honey.
viviparous: of seed, germinating while the fruit is still attached to the plant, as in Rhizophoraceae. cf. proliferous.
voucher: a specimen preserved (with documentation) to substantiate recorded observations, and to which reference can be made in the future to verify the identity of the plant.
wallum: sandy coastal sites with impeded drainage, usually supporting heath, scrubby communities or swamps.
warty (tuberculate): covered with wart-like protuberances. Fig. 16 C.
weed: a plant growing out of place or where it is not wanted; often characterized by high seed production and their ability to colonise disturbed ground quickly.
wet sclerophyll forest: an open forest in which mesomorphic (soft-leaved) shrubs form a layer below the trees (usually species of eucalypts). cf. dry sclerophyll forest.
whorl: a ring of leaves, bracts or floral parts borne at the same level on a stem or axis. Fig. 2 F. See also verticillate, pseudowhorled.
wing: (1) a membranous expansion of a fruit or seed which aids dispersal; (2) a thin flange of tissue on a stem or petiole; (3) a lateral petal in the family Fabaceae subfamily Faboideae.
woodland: a plant community dominated by short-boled trees (usually species of eucalypts) that are separated from each other and with grasses and other herbs forming a more or less continuous ground cover between them.
woolly: densely covered with matted long hairs. Fig. 14 F. cf. tomentose, villous.
wrinkled: covered with coarse lines or furrows. Fig. 16 G.
xeromorph: a plant having structural features usually associated with plants of arid habitats (such as hard or succulent leaves) but not necessarily drought-tolerant. cf. scleromorph, xerophyte.
xerophyte: a drought-tolerant plant.
xylem: the tissue, in a vascular plant, that conducts water and mineral salts from the roots to the leaves. cf. phloem.
zygomorphic: of a flower with the parts such as sepals and petals differing in shape, size, position and/or number so that the flower can be bisected in one plane only; bilaterally symmetrical. cf. actinomorphic.
|Privacy | Copyright | Disclaimer | About PlantNET | Cite PlantNET|