Oblong - Longer than wide and rounded at the ends, with nearly parallel sides for much of the length.

Obtuse - Rounded or blunt.

Opposite - Growing two to a node on opposite sides.

Orbicular - circular or approximately round.

Oval - Broadly elliptical.

Ovate - Shaped like an egg, with the narrow end at the apex.

Ovoid - Ovate.

Palmate - Compounded, divided, lobed, or ribbed so that the divisions or ribs spread out like fingers from a single point.

Panicle - A raceme compounded by branching.

Papolionaceous - Descriptive of a flower whose petals are arranged to resemble a butterfly.

Pedicel - The stalk of one flower in a cluster.

Peduncle - The stalk of a flower cluster or of a solitary flower.

Peltate - Having a stalk attached at or near the middle.

Perennial - Living through three or more seasons.

Persistant - Remaining on the plant; not falling off readily.

Petal - One unit of a corolla.

Petiole - The stalk of a leaf.

Pinna - (plural pinnae) - A leaflet or primary division o a pinnately compound leaf.

Pinnate - Having leaflets arranged in opposite rows along the petiole.

Pinnatifid - Split about halfway to the mid-rib, such that the divisions are pinnately arranged.

Pinnule - One of the divisions of a pinnate leaflet in a bi-pinnate leaf.

Pistil - The female reproduction organ of a flower.

Pod - Generally, a dry fruit that splits open.

Pome - A fleshy fruit with a central seed-bearing core. (e.g. apple).

Procumbent - Growing along the ground without rooting, and having ascending tips.

Prostrate - Growing flat along the ground.

Pubescent - Covered with down or soft, short hairs.