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Glossary of Botanical Terms:

A B C D-E F-H I-L M-O P Q-R S T-U V-Z
deciduous: (1) falling seasonally, e.g. of the leaves and bark of some trees, cf. caducous; (2) a plant losing its leaves for part of the year, cf. evergreen.

decompound: several times divided, compounded, e.g. of inflorescences where the order of branching is more than just the once compound.

decorticating: with bark peeling off.

decumbent: spreading horizontally with the ends growing upwards. Fig. 1 J.

decurrent: extending downwards beyond the point of insertion, e.g. of a petiole extending down the stem as a ridge. Fig. 4 C.

decurved: bent downwards and curved. cf. deflexed.

decussate: in pairs, with successive pairs borne at right angles to each other. Fig. 2 D.

definite: of a constant number; e.g. twice as many stamens as the petals or sepals (or less), or an inflorescence ending in a flower or an aborted floral bud. cf. indefinite.

deflexed: bent sharply downwards. cf. reflexed, decurved.

dehiscent: opening at maturity to release the contents, e.g. of a fruit, anther etc.

deltate: a 2-dimensional triangular shape.

deltoid: triangular, but a 3-dimensional solid.

dendritic: much branched, like the crown of a tree, e.g. of hairs. Fig. 15 F.

dendroid: tree-like in form but not in size. cf. arborescent.

dentate: toothed with rounded or sharp course teeth.

denticulate: finely toothed.

depauperate: impoverished.

depressed: flattened as if pressed down from the top or end, especially of 3 dimensional shapes.

determinate: (1) of growth or branching, with a bud or flower terminating the main axis; (2) of an inflorescence (= anthotelic), with the inflorescence or parts of the inflorescence ending in a flower or an aborted but distinctly floral bud, e.g. panicle, thyrsoid, dichasium, monochasium, Fig. 17 A, B, D & E. cf. indeterminate.

diadelphous: having the stamens united by their filaments into two groups, as in Fabaceae subfamily Faboideae. Fig. 20 F. cf. monadelphous.

diagnosis: a detailed description.

diaspore: the dispersal unit containing the results of sexual reproduction and including non-floral parts (if any)

dichasium: a cyme in which branches appear in regular opposite pairs. Fig. 17 D. cf. monochasium.

dichlamydeous: of a flower, having two whorls of perianth parts, a distinct calyx and corolla. cf. monochlamydeous.

dichotomous: divided into two equal forks, e.g. of the branching pattern of stems or veins. Fig. 9 G.

dicotyledons: a major group of angiosperms (flowering plants) characterized by the embryo usually having two (rarely more) cotyledons (seed leaves). cf. monocotyledons.

didymous: with stamens in 2 equal pairs.

didynamous: in 2 pairs of unequal length.

digitate (palmate): of a compound leaf with 3 or more leaflets arising from one point at top of petiole, Fig. 3 E.

dimorphic: occurring in two different forms.

dioecious: with male and female flowers on different plants. cf. monoecious.

diploid: having two lots of the basic set of chromosomes in the nucleus. cf. haploid, polyploid.

disarticulate: to separate at a joint.

disc: an outgrowth of tissue from the receptacle in the form of a ring or plate, sometimes divided into lobes or separate bodies, occurring between whorls of floral parts; generally glandular.

disc floret (disc flower): usually an actinomorphic flower produced in the central part of the head and with a tubular corolla with more or less equal lobes, as in most Asteraceae. cf. ray floret.

discoid: (1) disc-shaped, flat and circular; (2) having only disc florets.

discolorous: coloured differently on the two surfaces. cf. concolorous.

disjunct-opposite: a variant of opposite and decussate leaf arrangement in which during development the leaves of a pair become separated on the axis owing to elongation of the nodal region, often giving the appearance of ‘alternate’ leaf arrangement but distinguished by decussate, not spiral, sequence.

dissected: divided at least partially into segments.

distal: towards the free end or apex, away from the point of attachment.

distichous (2-ranked): arranged in two rows on opposite sides of a stem and in the same plane. Fig. 2 B.

distinct: separate, free.

diurnal: of flowers, opening only during daylight hours. cf. nocturnal.

divaricate: broadly spreading, more or less horizontal. Fig. 1 E.

division: the major taxonomic rank within the plant kingdom (in which the phylum is no longer generally recognised). cf. phylum

domatia: small structures on the lower surface of some leaves, usually consisting of depressions, partly enclosed by leaf tissue or hairs, usually located in the axils of the primary and secondary veins. Fig. 19 A & B.

dorsal (abaxial): relating to the back of an organ, i.e. the surface of a lateral organ facing away from the axis. cf. ventral.

dorsifixed: attached at or by the back. cf. basifixed, versatile.

dorsiventral: term describing leaves in which the upper and lower surfaces differ from each other in texture, presence of hairs, stomates etc. cf. isobilateral.

doubly toothed: with smaller regular teeth on the margins of larger teeth, as in some Prunus species. Fig. 8 D.

drupaceous: term describing a fruit which is a drupe or drupe-like.

drupe: an indehiscent succulent fruit derived from a single carpel in which the pericarp consists of three layers

drupelet: one drupe of a mature fruit composed of a cluster of small drupes, as in blackberries, the ‘seed’ being a pyrene. Fig. 18 X.

dry sclerophyll forest: an open forest in which scleromorphic (hard-leaved) shrubs form a layer below the trees (usually species of eucalypts). cf. wet sclerophyll forest.

duplicate: folded twice.

dyad: in twos, a pair.

ebracteate: without bracts.

echinate: spiny; bearing stiff, stout, prickly hairs.

ecotype: a plant or group of plants exhibiting certain characteristics of growth or flowering in response to particular environmental conditions.

edaphic: pertaining to the soil.

eglandular: without glands.

elaiosome: an oil body on some seeds; a feature of some seeds dispersed by ants.

ellipsoid: the 3-dimensional equivalent of elliptic.

elliptic: a 2-dimensional shape, oval in outline, broadest about the middle. Fig. 5 D.

elongate: lengthened; stretched out.

emarginate: having a broad shallow notch at the apex. Fig. 6 G.

embryo: the rudimentary plant present in a mature seed or within the archegonium after fertilization and some development.

embryo sac: the female gametophyte, produced within the ovule. Fig. 21.

emergent: of a plant, (1) rising above the surrounding plants, e.g. of a tree above the rainforest canopy; (2) rising above the surface of the water.

enation: epidermal outgrowth, projection.

endemic: having a natural distribution confined to a particular geographic region. cf. native.

endocarp: the innermost layer of the pericarp. cf. exocarp.

endosperm: nutritive tissue within the seed, usually surrounding the embryo or to one side of it, and formed within the embryo sac (in angiosperms a product of accessory fertilization). cf. perisperm.

entire: of a margin, neither dissected nor toothed. Fig. 8 A.

entomophilous: pollinated by insects.

ephemeral: short-lived annual.

epi-: a prefix: upon, as in epipetalous = borne on the petals.

epicalyx: a whorl of bracts just below the flower, resembling an extra calyx.

epicarp: the outermost layer of the pericarp.

epicormic: term describing buds, shoots or flowers borne on the old wood of trees, often applied to shoots arising from dormant buds after injury or fire, as in eucalypts.

epidermis: the outer layer of cells of an organ.

epigeal: of germination, having the cotyledon(s) emerging from the seed coat and becoming photosynthetic. cf. hypogeal.

epigynous: of floral parts, especially stamens, inserted on or above the ovary, and arising from tissue that is fused to the ovary wall. Fig. 12 B. cf. hypogynous, perigynous.

epilithic: of plants growing on rocks, e.g. some orchids.

epimatium: the ovule-bearing scale in some conifers, as in Podocarpus species.

epipeltate: of an anther that is dorsifixed (peltate) and in which the part of the anther that is prolonged downwards beyond the attachment point of the filament faces inwards in relation to the centre of the flower. cf. hypopeltate.

epipetalous: borne on the petals.

epiphyllous: growing on leaves, as plantlets on the leaves in some Crassulaceae.

epiphyte: a plant perched, but not parasitic, on another plant. Fig. 1 I. cf. lithophyte.

episepalous: of stamens, borne on the sepals.

equitant: of leaves, folded longitudinally with the two inner surfaces (representing the upper leaf surface) fused except towards the base where it clasps another leaf on the opposite side of the stem; one margin represents the leaf keel and the lamina is vertically orientated; as in Iris. Leaf arrangement, Fig. 2 E; cross section through equitant arrangement Fig. 11 B.

erect: (1) upright, e.g. of a shrub, Fig. 1 A; (2) perpendicular to a surface, e.g. of hairs.

eremean: pertaining to regions of low, irregular rainfall.

ericoid: of leaves, small and sharply pointed like those of the heaths.

erose: of margins, irregular as if nibbled. Fig. 8 E.

espatheate: without spathes.

eusporangiate: of ferns, having sporangia with walls more than one cell thick, originating from a group of cells. cf. leptosporangiate.

evergreen: a plant bearing leaves throughout the year. cf. deciduous.

ex-: a prefix: without, e.g. exstipulate, without stipules.

excentric: not centrally placed, without a fixed centre.

excurrent: running through to the apex and beyond as a mucro, e.g. of the midvein in a leaf.

exine: the outer layer of a pollen grain or spore.

exocarp: the combined epicarp and mesocarp of a fruit. cf. endocarp.

exotic: introduced from outside the area concerned, in the case of N.S.W. usually from overseas.

exserted: projecting beyond the surrounding objects, e.g. of stamens protruding beyond the perianth, or of valves projecting beyond the rim of a capsular fruit. cf. included.

exstipulate: without stipules.

extrafloral: not within the flower, usually applied to nectariferous glands, e.g. as those on the petiole in some Croton species and on the phyllodes of some wattles. Fig. 19 E–H.

extravaginal: of a tiller that grows by breaking through the subtending leaf sheath as it grows. cf. intravaginal.

extrorse: of stamens, dehiscing towards the outside of the flower. cf. introrse, latrorse.

f.: an abbreviation for (1) forma if preceding a taxon epithet, or (2) filius (son of) if following the author of the taxon (e.g. L.f. – son of Linnaeus).

facultative: of parasites, optional, cf. obligate.

falcate: sickle-shaped, e.g. of a leaf. Fig. 5 N.

family: a group of one or more genera believed to be related. cf. genus.

farina: a fine mealy powder on the surface of some plants.

fasciated: unnaturally and often monstrously connate or adnate, the coalesced parts often grossly proliferated in size and/or number; e.g. inflorescence of Celosia.

fascicled: arranged in bundles or clusters, e.g. leaves. Fig. 2 J.

feldmark: high altitude plant community characterized by scattered, dwarf prostrate plants with a mat or cushion habit.

felted: matted with very short interlocked hairs, having the appearance or texture of felt. Fig. 14 D. cf. tomentose.

fenestrate: windowed or provided with openings.

ferruginous: rusty, rust-coloured.

fertile: capable of reproducing itself; also used of portions of a plant or organ producing reproductive structures.

fertilization: the union of female and male gametes.

fibre: (1) a thread or thread-like body; (2) a long slender, thick-walled cell as in sclerenchyma tissue.

-fid: a suffix: divided to about half-way, e.g. 2-fid, 3-fid, bi-fid, tri-fid.

filament: (1) any thread-like body; (2) the stalk of a stamen.

filiform: thread-like. Fig. 5 A.

filius: (Latin) son, abbreviated to f.

fimbriate: having the margin fringed with long hair-like processes. Fig. 14 J. cf. ciliate.

fistula: the opening of a hollow leaf-base; through which the stem emerges.

flaccid: limp; tending to wilt. cf. turgid.

flexuous (flexuose): bent from side to side in one plane in zigzag form.

floccose: covered with soft woolly hairs which are entangled and tend to rub off.

flora: (1) the assemblage of plant taxa of an area; (2) a book dealing systematically with the plants of an area.

floral: belonging to or associated with a flower.

floral tube: see hypanthium.

floret: (1) a small flower, one of a spikelet or dense cluster, as in Asteraceae; (2) a grass flower, together with the lemma and palea that enclose it.

flower: the sexual reproductive structure of angiosperms, typically consisting of an axis bearing perianth parts, androecium and gynoecium. Fig. 12.

foliaceous: leaf-like.

-foliate: a suffix: number of leaves, as in bifoliate = with 2 leaves.

-foliolate: an adjective used with a number prefix to indicate the number of leaflets forming a compound leaf, e.g. bifoliolate, a leaf with 2 leaflets.

follicle: a dry fruit derived from a single carpel and opening along one suture. Fig. 18 F & G.

forb: a non-woody plant other than a grass, sedge, rush, etc. cf. herb.

forest: a plant community dominated by long-boled trees in close proximity. cf. woodland.

form (forma, Latin): the smallest taxonomic category, generally used for variations occurring among individuals of any population; sometimes abbreviated to f.

fovea: a pit. adj. foveate.

foveola: a small pit. adj. foveolate.

free: not united with any other organ.

free-central: of placentation, with the placenta along the central axis in a compound ovary without septa. Fig. 13 E & F.

frond: the leaf of a fern or cycad; sometimes used for a large compound leaf as in palms.

fruit: the seed-bearing structure in angiosperms, formed from the ovary after flowering. Fig. 18.

funicle: the stalk of the ovule.

fused: joined and growing together.

fusiform: spindle-shaped, i.e. narrower at both ends than at the middle.

Malesia: a phytogeographic region; including the Malay Peninsula, Malaysia, the Philippines, Indonesia and New Guinea.

mallee: (1) a growth form in which many stems arise from a lignotuber, usually applied to eucalypts; (2) of a plant community dominated by mallee eucalypts.

mangrove: a shrub or small tree growing in salt or brackish water and often with pneumatophores or aerial roots.

marcescent: withering without falling off.

marginal: (1) at or very close to the margin; (2) of placentation, with the placenta along the margin of a simple ovary, as in many legumes, Fig. 13 A.

maritime: belonging to the sea; confined to the sea-coast.

marsh: a waterlogged area; swampy ground without trees.

mealy: covered with coarse flour-like powder.

medifixed: attached by or at the middle, e.g. of anthers, attached to the filament at the middle of the connective.

megasporangium: a sporangium producing megaspores, = ovule in flowering plants.

megaspore: the spore in heterosporous plants that gives rise to a female gametophyte and is generally larger than the microspore; the spore usually not shed but remaining on the parent plant and developing in situ. cf. microspore.

megasporophyll: a specialised leaf upon (or in the axil of) which one or more megasporangia are borne. cf. microsporophyll.

meiosis: the two-stage division of a diploid nucleus in which the genetic recombination occurs and the number of chromosomes characteristic of the species is halved prior to the production of the sexual gametes; this process takes place once in every sexual life cycle.

membranous: thin and translucent.

mentum: a chin-like extension at the base of some orchid flowers formed by the column foot and the bases of the lateral sepals.

mericarp: one segment of a fruit that breaks at maturity into units derived from the individual carpels, sometimes called a coccus. Fig. 18 H & P. See schizocarp.

meristem: a growing region of a plant in which cells divide to produce new cells.

-merous: a suffix indicating that the number of parts in each floral whorl is divisible by the same basic number, e.g. a 5-merous flower is one with the number of sepals, petals and stamens divisible by 5; e.g. 5 sepals, 10 or 5 petals, and 5, 15 or 20 stamens. The number of carpels and their styles or stigmas often does not conform to the basic number.

mesic: requiring abundant water.

mesocarp: the fleshy part of the wall of a succulent fruit; the middle layer of the pericarp in a drupe.

mesomorphic: soft and with little fibrous tissue, but not succulent. cf. scleromorphic.

mesophyll: photosynthetic tissue of a leaf; of vegetation, characteristic of moist habitats and with soft, fairly large leaves predominating.

microphyllous: having small leaves that are usually hard and narrow.

micropyle: the small canal through the integuments (outer layers of tissue) of an ovule, usually at the point furthest away from the funicle (ovule stalk), persisting as a pore in the seed coat.

microspecies: segregate species of a larger species or species-aggregate, e.g. see Rubus fruticosus.

microsporangium: the sporangium producing the microspores, within the anthers in angiosperms.

microspore: the spore in heterosporous plants that gives rise to a male gametophyte and is generally smaller than a megaspore; microspores are shed at maturity. cf. megaspore, pollen.

microsporocarp: a body containing the microsporangium, e.g. as in some ferns.

microsporophyll: a specialised leaf upon (or on the axil of) which one or more microsporangia are borne

midrib: term applied to the midvein or primary vein, especially when it is prominently raised or depressed.

midvein: the primary vein which runs from the base to the apex of the lamina, usually the most prominent vein, from which arise the secondary or lateral veins.

minute: very small, usually less than 1 mm long.

mitra: a pointed cap or hood.

monadelphous: of stamens, with their filaments fused into one group, as in many Malvaceae. Fig. 20 G. cf. diadelphous.

moniliform: of a pod or other organ: constricted , so as to resemble a necklace of beads; e.g. hairs, Fig. 15 E.

mono-: a prefix, one: as in monotypic, a genus with 1 species.

monochasium: a cyme with the branches arising singly. Fig. 17 E. cf. dichasium.

monochlamydeous: of a flower, having only one whorl of perianth parts. cf. dichlamydeous.

monocotyledons: a major group of angiosperms, characterized by the embryo usually having one cotyledon (seed leaf). cf. dicotyledons.

monoecious: having male and female flowers on the same plant.

monophyletic: derived from a single ancestral line. cf. polyphyletic.

monopodial: with a persistent terminal growing point producing many lateral organs progressively. cf. sympodial.

monotypic: of a genus, having only one species. cf. unigeneric.

motile: actively moving; self-propelled.

mucilage: a slimy, gummy substance sometimes secreted by hairs or glands. adj. mucilaginous.

mucro: a sharp, usually suddenly constricted, apical point.

mucronate: having a mucro. Fig. 6 K.

mucronulate: a small mucro on obtuse apex.

multicellular hairs: hairs consisting of more than 1 cell.

multiple fruit: a cluster of fruits produced from more than one flower and appearing as a single fruit, often on a swollen axis, as in Moraceae. Fig. 18 Y & Z. e.g. syncarp, syconium. cf. aggregate fruit.

muricate: of a surface, rough with pointed protuberances or short hard tubercles. Fig. 16 B.

muriculate: minutely muricate, rough with minute, short, hard points.

muticous: blunt, awnless, lacking a point.

mycorrhiza: a symbiotic association between a fungus and a plant root.

raceme: a simple inflorescence ending in a non-floral bud and in which the flowers are stalked, i.e. an indeterminate inflorescence. Fig. 17 H. cf. raceme-like, spike.

raceme-like: applied to a simple inflorescence ending in a floral bud in which the flowers are stalked, i.e. resembling a raceme but determinate; also used for conflorescences of similar form, particularly where there has been reduction from more complex types. cf. raceme, spike-like.

rachilla: the axis of a grass spikelet above the glumes, also the axis in sedge spikelets.

rachis: the axis of an inflorescence, pinnate leaf, or of a pinna in a bipinnate leaf.

radical (basal): of leaves, clustered at the base of the stem. Fig. 2 I. cf. cauline, rosette.

radicle: the portion of an embryo that gives rise to the primary root system of a plant.

rainforest (closed forest): a forest dominated by broad-leaved trees with dense crowns that form a continuous layer (canopy) and with one or more of the following growth forms

ramiflory: the production of flowers and fruits behind the current foliage on woody branches formed in previous, but recent, seasons. adj. ramiflorous. cf. cauliflory.

rank: (1) a vertical row; (2) leaves that are 2-ranked are in 2 vertical rows, and may be alternate or opposite.

raphe: the part of the stalk of an anatropous ovule that is fused along the side of the ovule.

raphides: needle-like crystals that occur in bundles in the vacuoles of some plant cells.

ray floret (ray flower): a zygomorphic flower in many species of the family Asteraceae, usually formed towards the periphery of the head and with the corolla extended into a strap-shaped ligule. cf. disc floret.

receptacle: the often more or less expanded top of the stalk on which a flower or flower-head arises, Fig. 12 A; an axis on which sporangia arise in ferns.

recurved: curved backwards (and hence usually downwards), e.g. of the margins of a leaf. Fig. 10 D. cf. revolute, incurved, reflexed.

reflexed: bent sharply backwards (and hence usually downwards). cf. deflexed, inflexed.

regular: see actinomorphic.

reniform: kidney-shaped. Fig. 5 G.

replum: a longitudinal partition in fruits of the family Brassicaceae, see silicula, siliqua.

resinous: with a hardened sticky surface.

resupinate: twisted through 180° as in the ovary of most orchid (family Orchidaceae) flowers.

reticulate: forming a network or reticulum; e.g. of veins, Fig. 9 H.

retinaculum: (1) a hook-like structure to which another structure is tethered, as in Orchidaceae and Asclepiadaceae (the structure to which pollen masses are attached) or in Acanthaceae (the persistent stalk of an ovule); (2) the marginal outgrowth from a spadix, as in Zosteraceae. pl. retinacula.

retrorse: directed backwards (and thus often downwards).

retuse: having the apex rounded and with a small notch. Fig. 6 H.

revolute: rolled backwards (and thus often downwards), e.g. of the margins of a leaf. Fig. 10 E. cf. recurved, involute.

rhizoid: a thread-like, unicellular absorbing structure, in fern gametophytes and some non-vascular plants.

rhizome: an underground stem, usually growing horizontally. adj. rhizomatous. Fig. 1 N.

rhombic: having the form of a 2-dimensional diamond-shaped figure. Fig. 5 H.

rhomboid: having the form of a 3-dimensional diamond-shaped solid.

riparian: of plants growing by rivers or streams.

root: part of the underground axial system of a plant which does not bear leaves and tends to grow downwards or laterally in the soil. See also adventitious, aerial root.

rootstock: a swollen region at the junction of root system and stem, mostly below ground level.

rosette: a radiating cluster of leaves, usually close to the ground at the base of a plant. Fig. 2 I. See also radical.

rostellum: in orchids, a projection of the upper edge of the stigma in front of the anthers.

rostrate: beaked.

rosulate: clustered into a rosette.

rotate: term applied to a shortly tubular corolla with spreading lobes or limbs.

rudimentary: imperfectly developed and non-functional.

rugose (wrinkled): covered with coarse lines or furrows. Fig. 16 G.

rugulose: with tiny wrinkles.

ruminate: (1) of a surface or tissue, with an irregular, involuted outline, as in a rumen; (2) mottled in appearance.

runcinate: term describing a pinnatifid or pinnatisect leaf with sharply incised lobes or teeth pointing towards the base. Fig. 5 Q.

runner: a slender prostrate stem having a bud at the end which sends out leaves and roots.

rush: a plant belonging to the family Juncaceae or, more loosely, to various monocotyledons.

taproot: the main, descending root of a plant that has a single, dominant root system.

taxon: a term used to describe a member of any taxonomic category, e.g. genus, species. pl. taxa.

taxonomy: the study of the principles and practices of classification, the establishing and defining of relationships; often used interchangeably with systematics, but strictly taxonomy is only part of systematics.

tendril: a long slender, coiled organ derived from an axis or leaf, or from part of one of these.

tepal: a free segment of a perianth that is not differentiated into a calyx and corolla.

terete: cylindric and elongated. Fig. 10 H.

terminal: at the apex.

terminal petiolule: the stalk of the terminal leaflet of a pinnately 3-foliolate leaf or an imparipinnate leaf; the stalk is usually jointed at the point where the rachis extension beyond the last leaflet meets the true petiolule of the leaflet. Fig. 3 C & K.

ternate: in threes, e.g. of a single leaf, having the leaflets arranged in groups of three. Fig. 3 K & L. cf. biternate.

terrestrial: of the land as opposed to living in water. cf. aquatic.

tessellated: with colours or shapes arranged in squares to give a chequered appearance, e.g. of bark.

testa: the seed coat.

tetrad: a group of four; as in four pollen grains remaining together at maturity in Ericaceae subfamily Styphelioideae.

tetradynamous: of an androecium, consisting of four stames of the same length and two of a different length; as in many Brassicaceae.

tetramerous: of a flower, having four segments in each perianth whorl, and usually in each whorl of stamens also.

tetrasporangiate (4-sporangiate): of an anther in which there are 4 pollen sacs (sites of pollen grain formation or microsporangia). cf. unisporangiate.

thallus: the vegetative body of a plant that is not differentiated into organs such as stems and leaves, e.g. algae, the gametophytes of many liverworts, and family Lemnaceae.

thorn (spine): a stiff process with a sharp point, formed by a modification of a plant organ that contains vascular tissue, e.g. a lateral branch or a stipule. cf. prickle.

throat: of a corolla tube or hypanthium, the top where the tube joins the lobes.

thyrse: a compound inflorescence ending in a vegetative (non-floral) bud and with mixed types of branching, the main axis bearing several or many lateral cymes. Fig. 17 C.

thyrsoid: a compound inflorescence which ends in a flower and in which the main axis is raceme-like and the lateral ones cymose, i.e. similar to a thyrse except for the terminal flower. Fig. 17 B.

tiller: the shoot of a grass, usually lateral and basal and more or less erect.

tomentellous: minutely tomentose.

tomentose: covered with dense intertwined hairs. Fig. 14 E. n. tomentum. cf. woolly.

tomentum: a dense covering of intertwined hairs. Fig. 14 E. adj. tomentose.

toothed: of margins, regularly or irregularly incised. Fig. 8 C.

torus: see receptacle.

trabeculate: cross-barred.

tree: a woody plant usually with a single distinct trunk and generally more than 5 m high.

tri-: a prefix: in threes, as in: trifoliolate, having three leaflets; trimerous, with flower parts arranged in threes.

triad: a three-flowered inflorescence of dichasial form. Fig. 17 F.

triangular: a 2-dimensional shape, 3-angled and 3-sided. Fig. 5 K.

tribe: a taxonomic grouping, in rank between family and genus.

trichome: a hair, bristle, scale or other such outgrowth of the epidermis. Fig. 14 & Fig. 15.

trichotomous: branching almost equally into three parts.

trifid: deeply divided into three parts.

trifoliate: having three leaves. cf. trifoliolate.

trifoliolate: of a leaf, having three leaflets. Fig. 3 K & L. See also palmately trifoliolate, pinnately trifoliolate.

trigonous: triangular in cross-section and with the angles somewhat rounded. Fig. 10 F. cf. triquetrous.

trimerous: of a flower, having three segments in each perianth whorl and usually in each whorl of stamens also.

trimorphic: occurring in three different forms. cf. dimorphic.

tripinnate (3-pinnate): of a compound leaf, with lamina pinnately divided three times, i.e. the pinnules are again pinnately divided. Fig. 3 A. cf. bipinnate.

triplicate: folded three times.

triquetrous: triangular in cross-section and sharply angled; with three distinct longitudinal ridges. Fig. 10 G. cf. trigonous.

tristylous: heterostylous species with styles of 3 different lengths (short, mid, long).

trullate: ovate, but angled; like a brick-layer’s trowel; inverse kiteshaped.

truncate: with an abruptly transverse edge as if cut off, e.g. of a lamina apex (Fig. 6 F), or base (Fig. 7 D).

tuber: an underground storage organ formed by the swelling of a stem, e.g. a potato. adj. tuberous.

tubercle: a small wart-like outgrowth, e.g. forming the base of a hair.

tuberculate (warty): having the surface rough with tubercles or small wart-like outgrowths. Fig. 16 C.

tuberoid: a storage organ which is a tuber-like thickening of a root (and generally bears no lateral eyes) as in many terrestrial orchids.

tuberous: swollen; of roots tuber-like.

tumid: swollen; inflated.

tunicate: with coats or tunics; as in bulbs or corms covered with a thin membranous or fibrous outer layers.

turbinate: top-shaped.

turgid: swollen owing to high water content.

turion: a specialized dwarf shoot with modified leaves, and formed by some species in winter. Turions mostly fall from the parent plant, remain dormant over winter, and then sprout to form new individuals.

tussock: a large clump or tuft, usually of a perennial herb, especially grasses.

two-ranked (2-ranked): arranged in two rows on opposite sides of a stem and in the same plane. Fig. 2 B.

type: the designated representative of a taxon constituting a fixed point for the application of its name, for determining priority of usage.

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