D

Deciduous: Falling off or subject to fall, applied to leaves, petals, etc.

Decumbent: Reclining or lying on the ground.

Decurrent: Extending down and adnate to the stem, as occurs in some leaves.

Decussate: Opposite leaves in four rows up and down the stem.

Dehiscent: Opening spontaneously when ripe, e.g., capsules, anthers.

Deltoid: Shaped like an equal-sided triangle.

Dentate: Margin prominently toothed with the pointed teeth directed outwards.

Denticulate: Finely dentate.

Determinate: When the terminal or central flower of an inflorescence opens first and the prolongation of the axis is arrested.

Diadelphous: In two bundles.

Dichasium: A cyme in which the branches are opposite and approximately equal.

Dichogamous: Maturation of stamens and pistils at different times.

Dichotomous: Forked regularly in two.

Diclinous: Unisexual and requiring two flowers to represent both sexes.    

Dicotyledon: Angiosperms with two cotyledons or seed-leaves.

Didynamous: In two pairs of unequal length.

Digitate: A compound leaf whose leaflets diverge from the same point like the fingers of a hand.

Dimorphic: Of two forms, as may occur with branches, etc.

Dioecious: With unisexual flowers and with the staminate and pistillate flowers on different plants.

Diploid: With two sets (genomes) of chromosomes, as occurs in somatic or body cells; usually written 2n, having twice the basic chromosome number of the haploid germ cells.

Disc: A fleshy or elevated development of the receptacle, within the calyx or corolla or stamens, often lobed and nectiferous.

Dissected: Divided into many slender segments.

Distal: Farther from the place of attachment. 

Distichous: Regularly arranged in two opposite rows on either side of the stem.

Dominant: A gene which expresses itself in the hybrid to the exclusion of its contrasting recessive; the chief constituent of a particular plant community.

Dorsal: Back; referring to the back or outer surface of a part or organ.

Dorsifixed: Attached by the back, as occurs in anthers to a filament.

Drupe: A fleshy one-seeded indehiscent fruit with the seed enclosed in a strong endocarp.