deciduous

a. falling off at the end of the current growing season

decumbent

a. reclining on the ground but with the tip ascending

diatom

n. a single-celled algae, capable of photosynthesis, forming a thin shell of silica which persists after the death of the organism

dichogamous

a. where perfect (having both male and female characteristics) flowers develop in phases, with the maturation of the stamens(pollen dispersal from anthers) and pistils(stigma receptivity) occurring at different times to prevent self-polination

dimorphic

a. having two forms

dioecious

a. having imperfect flowers where the staminate(male) and pistillate(female) flowers are borne on separate plants

disk

n. in the Asteraceae, the tubular flowers

n. an outgrowth from the receptacle of a flower, surrounding the base of the ovary, often derived by reduction and modification of the innermost set of stamens

diurnal

a. with animals: active during the day; with plants: having flowers that open during the day and close at night