FLORA OF THE DISTRICT OF COLUMBIA. 301 



Oblique. Slanting; making an acute angle with the axis. 

 Oblong. Longer than broad, Avith the sides nearly parallel. 

 Obovate. Inverted-ovate. 

 Obovoid. Inverted-ovoid. 



Obsolete. Not evident; in a rudimentary or vestigial state. 

 Obtuse. Not sharply pointed; blunt or rounded at the end. 

 Oerex. The membranous, sheathing, united stipules of Polygonaceae. 

 Opaque. Dull; not shining or translucent. 



Opposite. Referring to leaves or similar organs which arise on the stem in twos, one 

 on each side of the node; also, one part above or before another, as a stamen in 

 front of a petal. 

 Orbicular. Essentially circular. 

 Ovary. The ovule-bearing part of the pistil. 

 Ovate. Ha\dng the outline of a hen's egg in longitudinal section, with the broad end 



downward. 

 Ovoid. Shaped like a hen's egg. 



Ovule. The body which after fertilization develops into the seed. 

 Palea. The bract of a floret of gi-asses standing between the flower and the rachilla 



or axis of the spikelet. 

 PaUt. See palea. 

 Palmate. Refemng to organs which are radiately lobed or di\dded, suggesting the 



outspread fingers of the hand. 

 Panduriform. Fiddle-shaped. 

 Panicle. A compound inflorescence with pedicellate flowers; the compound fertile 



parts of certain dimorphous ferns and fern allies. 

 Paniculate. Borne in a panicle; resembling a panicle. 

 Papilionaceous. Referring to the peculiar irregular corolla of the Fabaceae, consisting 



of standard, wings, and keel. 

 Papillose. Bearing minute blunt protuberances. 

 Pappus. The peculiar calyx limb of Asteraceae. etc., surmounting the achene and 



commonly bristle-like, awnlike, or feathery. 

 Parasitic. Growing on other organisms and deriving nourishment from them. 

 Parietal. Borne on the wall of a capsule, cr pertaining to it. 

 Parted. Cleft nearly to the base. 



Parthenogenetic. Developing without the agency of fertilization. 

 Pectinate. Regularly pinnatifid into niimerous narrow, closely set segments; having 



organs or members arranged in a pectinate or comblike manner. 

 Pedate. Palmately divided or parted, but having the lateral segments two-cleft. 

 Pedicel. The support of a single flower of a flower cluster; in grasses, the support of 



a single spikelet. 

 Pedicellate. Borne on a pedicel. 



Peduncle. A main flower stalk supporting a flower cluster or a solitary flower. 

 Pedunculate. Borne upon a peduncle. 

 Pellucid. Transparent or somewhat so. 

 Peltate. Attached to its stalk at some point of the lower surface, instead of at the 



margin. 

 Pendulous. More or less hanging. 



Percurrent. Extending throughout the entire length of the organ. 

 Perennial. Living year after year. 



Perfect. Referring to flowers which have both pistil and stamens. 

 Perfoliate. Referring to leaves whose clasping bases, are united, as if pierced by 



the stem. 

 Perianth. The floral envelope, consisting of the calyx and corolla, however incom- 

 plete or modified. 



