Placenta. Any part of the interior of the ovary which bears ovules.
Plane. Flat; with a flat surface or surfaces.
Plicate. Folded into plaits, usually lengthwise.
Plumose. Having fine hairs on each side, like the plume of a feather, as the pappus-bristles of Thistles.
Plumule. The bud or growing point of the embryo.
Pod. Any dry and dehiscent fruit.
Pointed. Acuminate.
Pollen. The fecundating grains contained in the anther.
Polliniferous. Bearing pollen.
Pollinium (pl. Pollinia). A mass of waxy pollen or of coherent pollen-grains, as in Asclepias and Orchids.