280 American Midland Naturalist Monograph No. 2 



Perigynous. Boine arcund the ovary and not at its base, as in flowers in which 



perianth and stamens are borne on the rim of the hypanthium. 

 Petal. One of the parts of an apopetalous corolla. 

 Petaliferous. Petal-bearing. 

 Petiolate. Having a petiole. 

 Petiole. A leaf-stalk. 

 Petiolulate. Having a petiolule. 

 Petiolule. Stalk of a leaflet. 

 Phyllopodic. The basal leaves of the fertile stems normally blade-bearing, as in 



species of Carex. 

 Pilose. Pubescent with soft long straight trichomes. 

 PiLOSULOUS. Minutely pilose. 

 Pinna. A primary division of a pinnate leaf. 

 Pinnate (leaf). Compound, with the leaflets on each side of a common petiole or 



rachis. 

 PiNNATIFID. Cleft or divided in a pinnate manner, the sinuses or lobes narrow or acute. 

 Pinnule. One of the smaller subdivisions of the primary divisions of a pinnately 



compound leaf, especially of ferns. 

 Pistil. The ovule-beanng part of a flower, comprising ovary, style, and stigma; con- 

 sisting of a single carpel (simple pistil) or of two or more partly or wholly fused 

 carpels (compound pistil). 

 Pistillate flower. A flower with a pistil but no stamens. 

 Placenta. Any part of the interior of the ovary which bears the ovules. 

 Plano-convex. Plane on one side and convex on the other. 

 Plicate. Folded like a fan. 

 Plumose. Feathery; furnished with long hairs, as the beak of the achene in Clematis, 



or the pappus of some Compositae. 

 Pollen. Microspores, or partially developed male gametophytes, formed in the anthers 



of seed plants; the powdery contents of an anther. 

 Polygamous. Bearing unisexual and bisexual flowers on the same plant. 

 PoLYPETALOUS. With petals separate. 

 Pome. An accessory fruit composed of the pericarp and enlarged receptacle, as in the 



apple. 

 Prickle. A sharp-pointed outgrowth of the cortex and epidermis of a stem or leaf, 



as in rose, blackberry, etc. 

 Procumbent (stem). Trailing on the ground, but not rooting at the nodes. 

 Proliferous. Producing offshoots, sometimes abnormal, as when carpels or stamens 



give rise to leafy shoots. 

 Prostrate. Lying flat on the ground. 

 Puberulent. Minutely pubescent. 



Pubescent. Covered with pubescence, an indument of hairs (trichomes). 

 Pulverulent. Appearing as if covered with powder or dust. 

 Punctate. Marked with small dots or translucent glands. 

 PuncticULATE. Minutely punctate. 



Pungent. Terminating in a rigid sharp point; also of acrid flavor. 

 Pyriform. Pear-shaped. 



QuADRlFOLiATE. Four-leaved. 

 QuADRIFOLIOLATE. Having four leaflets. 



Raceme. An indeterminate inflorescence with pedicellate flowers on a more or less 

 elongated axis. 



Racemose. In a raceme, or resembling a raceme. 



Raciiilla. a secondary axis or rachis; in the grasses and sedges the axis that bears 

 the flowers. 



Rachis. An axis bearing flowers or leaflets. 



Radiate. Spreading from a common center; in the Compositae, a head with ray- 

 flowers. 



Ray. The branch of an umbel; the marginal flowers (ray-flowers) of an inflorescence 



