Glossary of Botanical Terms:

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.

  Privacy | Copyright | Disclaimer | About PlantNET | Cite PlantNET