Jones: Flora of Illinois 279 



MuCRONATE. Tipped with a short abrupt point or mucro. 



MuCRONULATE. Minutely mucronate. 



Multiple fruit. A cluster of matured ovaries produced by separate flowers. 



MuRlCATE. Roughened with short hard points. 



Naturalized (nat.). Although not native in the region, growing spontaneously and 



well established as a component of the flora. 

 Neutral. Devoid of stamens and functioning pistil. 

 Nodose. Provided with knots or internal transverse partitions, as the leaves of some 



species of Juticus. 

 Node. The joint of a stem where the leaves are inserted. 

 Nut. An indehiscent, dry, one-seeded, hard-walled fruit, produced from a compound 



ovary. 

 Nutlet. A little nut; one of the achene-like parts of the fruit of Boraginaceae, 



Verbenaceae, Labiatae, etc. 



Ob — . A Latin prefix, usually signifying inversion, as obcordate (inversely heart- 

 shaped), obianceolate (inversely lanceolate), obovate (inversely ovate), etc. 



Obtuse. Blunt, rounded. 



Opposite. Inserted on opposite sides of an axis, as leaves, when there are two at one 

 node. 



Orbicular. Circular; round in outline. 



Oval. Broadly elliptical, with the width more than half the length. 



Ovary. The basal part of the pistil containing the ovules; the immature fruit. 



OvATi;. Having the outline like the median longitudinal section of a hen's egg, the 

 broader end downward. 



Ovoid. A solid body ovate in longitudinal section. 



Ovule. The primordium of a seed in the ovary; the organ which may develop after 

 fertilization into the seed. 



Palet. The upper bract which with the lemma encloses the flower in grasses. 

 Palmate (leaf). Radiately lobed or divided, with three or more veins arising from 



one point. 

 Panicle. A compound raceme. 



Paniculate. Borne in panicles, or resembling, a panicle. 

 Papilionaceous. Referring to the peculiar irregular corolla of many Leguminosae, 



consisting of a lalrge upper petal f standard), two oblique lateral petals (rvings), 



and the two lower ones connivent into a f^eel. 

 Papillose. Covered with papillae, which are small protuberances. 

 Pappus. The modified limb of the calyx in Compositae, forming a crown of variable 



structure at the summit of the achene. 

 Parasite. An organism which derives nourishment from another living organism. 

 Parietal. Borne on or pertaining to the wall of the ovary or fruit. 

 Pectinate. Comb-like; pinnatifid with narrow, closely set segments. 

 Pedate. Palmately divided or parted, with the lateral divisions two-cleft. 

 PeU)ICEL. The stalk of a single flower in a cluster. 

 Peduncle. The primary flower stalk which supports either a cluster of flowers, or a 



single flower. 

 Pellucid. Clear, transparent, or translucent. 

 Peltate. Shield-shaped; said of a leaf when the petiole is attached to the under side 



away from the margin or usually not far from the center. 

 Pendent. Hanging down ; pendulous. 



PeNICILLATE. Bearing a little tuft of hairs, especially at the tip. 

 Perrennial. a plant, or part of a plant, which persists for more than two seasons. 

 Perfect (flower). Having both stamens and carpels; bisexual. 

 Perfoliate. Said of a leaf when the stem appears to pass through its base. 

 Perianth. The floral envelope; a term commonly used when there is no clear distinc- 

 tion between calyx and corolla. 

 Pericarp. The wall of the ripened fruit. 

 Perigynium. The inflated sac (bract) enclosing the pistillate flower in Carex. 



