Spring Flora of Oklahoma 
215 
Oddly pinnate—Pinnately compound and having a terminal leaflet. 
Orbicular—Nearly circular in outline. 
Orthotropous—A straight ovule, having the hilum and micropyle at 
opposite ends. 
Oval—Broadly elliptic. 
Ovary—The female organ of reproduction; an egg-producing organ. 
Ovate—Shaped like the longitudinal section of a hen’s egg. 
Ovule—The megasporangium of a seed plant which later develops 
into a seed. 
Palmate—Diverging like the fingers of a hand. 
Panicle—A compound inflorescence of the racemose type usually of 
pyramidal form. 
Paniculate—Borne in a panicle; resemblirg a panicle. 
Papilionaceous—Applied to the zygomorphic flowers of the Bean 
family. 
Papillose—With minute blunt projections. 
Pappus—The bristles, awrns, teeth, etc., on the top of an acheile. 
Parietal—Borne on the wall of the ovulary, or pertaining to it. 
Parted—Deeply cleft. 
Pedicel—The stalk of a flower in a flower-cluster. 
Peduncle—The stalk of a flower or flower-cluster. 
Peltate—'Shield-shaped, as a leaf with the petiole attached at or 
near the centre of the blade. 
Pendulous—Applied to an ovule which hangs downward from the 
side of the ovary. 
Pepo—A fruit with a hard outer rind, as a gourd or melon. 
Perennial—Growing for many years. 
Perfect—A flower having both stamens and carpels. 
Perfoliate—Leaves so clasping the stem as to appear as if pierced 
by it. 
Perianth—The calyx and corolla taken collectively. 
Pericarp—The wall of a fruit; the carpel wall. 
Perigynous—Having the sepals, petals and stamens borne on a disk 
or hypanthium surrounding the gynecium. 
Persistent—Remaining attached after the growing period. 
Petal—One of the leaves of the corolla. 
Petiole—The stalk of a leaf. 
Pilose—With long soft hairs. 
Pinna—The primary division of a pinnately-compound leaf. 
Pinnate—Leaves divided into leaflets or segments along a common 
axis. 
Pinnatifid—Pinnately cleft to the middle or beyond. 
Pinnule—A division of a pinna in a compound leaf. 
Pistil—The seed-bearing organ of the flower, consisting of the ovary, 
stigma, and style when present. 
