deciduous: falling seasonally, e.g. of the leaves or bark of some trees. cf. evergreen.

declinate: angled downwards or forwards. cf. decurved.

decompound: more than once compound.

decumbent: spreading horizontally but then growing upwards.

decurrent: extending downwards beyond the point of insertion, e.g. of a leaf lamina extending downwards to form a flange along the petiole.

decurved: angled downwards and curved or curled. cf. declinate.

decussate: in opposite pairs, with successive pairs borne at right angles to each other.

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

deflexed: bent abruptly downwards. cf. inflexed.

dehiscent: breaking open at maturity to release the contents.

deltoid (= deltate): triangular with the sides of about equal length.

dendritic: of a trichome, with branches arising along the main axis, i.e. tree-like.

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

dentate: toothed.

denticle: a small tooth; in Coprosma (Rubiaceae), thick papillate tubercles on the margin of the interpetiolar stipules.

denticulate: finely toothed.

depressed: flattened as if pressed down from the top or end.

determinate: of growth or branching, with a bud or flower terminating the growth of the main axis; of an inflorescence, see definite.

dextrorse: turned towards the right. cf. sinistrorse.

diadelphous: having the stamens united into two groups, or all but one united in a group and one free. cf. monadelphous.

diaphanous: extremely thin and transparent.

dichasium: a cymose inflorescence with opposite branching below the flower which terminates each axis. cf. monochasium.

dichlamydeous: of a flower, having two whorls of perianth parts. cf. monochlamydeous.

dichotomous: forking into two equal branches resulting from division of the growing point.

diclinous: having the stamens and the carpels in separate flowers. cf. monoclinous.

dicotyledon: a flowering plant whose embryo has two (rarely more) cotyledons (seed leaves). cf. monocotyledon.

didymous: borne in pairs; of anthers, having two lobes, with scarcely any tissue connecting them.

didynamous: of an androecium, consisting of four stamens, two being distinctly longer than the other two. cf. tetradynamous.

digitate: branching from the axis or stalk like the fingers of a hand.

dimidiate: appearing to be halved, as when half an organ is so much smaller than the other that it seems absent.

dimorphic: of two different forms.

dioecious: having the male and female reproductive structures on separate plants. cf. monoecious.

diplecolobous: of cotyledons in a seed, twice folded transversely.

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

disc: a plate or rim of tissue, derived from the receptacle of a flower, occurring between whorls of floral parts.

disc floret: an actinomorphic flower in Asteraceae. cf. ray floret.

discolorous: of different colours; of leaves, having the two surfaces different in colour; variegated. cf. concolorous.

dissepiment: a partition (septum) within an ovary or fruit, derived by fusion of adjacent carpels.

distal: remote from the point of origin or attachment. cf. proximal.

distichous: arranged in two rows on opposite sides of a stem and thus in the same plane.

diurnal: of flowers, opening only during daylight hours.

divaricate: widely spreading.

division: the major taxonomic rank within the Plant Kingdom. Alternative name for phylum.

domatia: small structures on the lower surface of a leaf in some woody dicotyledons, located in the axils of the primary veins and usually consisting of depressions partly enclosed by leaf tissue or hairs. sing. domatium.

dorsal: of a lateral organ, (relating to the side) facing away from the axis, i.e. the 'back'; of a thallus, facing away from the substratum. cf. ventral.

dorsifixed: attached at or by the back.

dorsiventral: having structurally different upper and lower surfaces. cf. isobilateral.

drupe: a succulent fruit formed from one carpel, having the seed(s) enclosed in an inner stony layer of the fruit wall. adj. drupaceous (which is often used to mean drupe-like but not strictly a drupe). cf. berry, pyrene.

duplicate: folded twice.

Back to Glossary Index


This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be reproduced by any process without prior written permission from Australian Biological Resources Study. Requests and inquiries concerning reproduction and rights should be addressed in the first instance to the Executive Editor - Flora. These pages may not be displayed on, or downloaded to, any other server without the express permission of ABRS.


Last updated on 13 May 1999.

Australian Biological Resources Study