Deciduous
A non-evergreen plant that loses it leaves after its growing season.
Decumbent
A plant structure that grows along the ground with the tip curving upward (See also Prostrate).
Decurrent
A leaf blade that attaches to and runs down the stem to the connecting point.
Decussate
Leaves arranged in opposite pairs, rotating 90º at every node (See also Distichous).
Dehiscent
An organ splitting open when ripe; commonly used for seed pods and anthers (for pollen release).
Deltoid
Triangular like the Greek letter Delta, bottom two corners can be angular or rounded.
Dentate
Square or rectangular teeth along margin pointing outward (See also Serrate and Crenate).
Denticulate
Diminutive of dentate with very small square or rectangular teeth.
Determinate
Predefined end of growth; in flowers the terminal flower blooms first stopping the elongation of the main axis.
Dialated
Expanded or flaring open.
Dichotomous
Veins extend from a common point forming a “y” pattern and fanning out as each vein branches into two.
Dioecious
Plants that have all male or all female flowers but not both; often referred to as having “two houses”. Dioecious plants are thus either male or female.
Dissected
A part of a plant that is deeply divided into narrow segments (See also Incised).
Distichous
Leaves are arranged in two ranks along either side of a stem (See also Decussate).
Divergent
Splitting or spreading apart.
Divided
Split, cut, or lobed all the way to the base or midrib.
Doubly-Serrate
Forward pointing teeth with each tooth (serration) having smaller serrations on it.
Downy
Covered by a mass of small fine hairs that are soft.