Monographs Details:
Authority:
Acevedo-RodrÃguez, Pedro & collaborators. 1996. Flora of St. John, U.S. Virgin Islands. Mem. New York Bot. Gard. 78: 1-581.
Acevedo-RodrÃguez, Pedro & collaborators. 1996. Flora of St. John, U.S. Virgin Islands. Mem. New York Bot. Gard. 78: 1-581.
Family:
Cyperaceae
Cyperaceae
Description:
Genus Description - Perennials or sometimes annuals, vegetatively diverse; roots fibrous; culms cespitose or borne singly, 3-angled or obscurely so, sometimes channeled distally, occasionally cylindrical, smooth or sometimes scabrous distally, glabrous or sometimes hirsute. Leaves basal or basal and cauline; blades flattened or folded, sometimes inrolled, linear or filiform, herbaceous or occasionally stiff, glabrous, hirsute, or occasionally scabrous distally, rarely papillose, the margins and ventral midvein usually scabrous, ciliate, or with setose hairs; sheaths eligulate, rarely with a narrow band of trichomes, sometimes whitened at base, the inner band usually membranous, splitting with age. Inflorescence terminal or both terminal and lateral, paniculate, corymbose, or congested and headlike; involucral bracts leaflike, sometimes whitened at base; branches cylindrical, 3-angled, or subcompressed, ribbed, scabrous, ciliate, or smooth on margins; spikelets ovate, elliptic, or lanceolate, sometimes cylindrical or subcompressed, primarily 1- to several-flowered; scales spirally imbricate, ovate to lanceolate, finely nerved, with a single, distinct midrib, light to dark brown, sometimes whitish, the lower 2 to many, sterile. Flowers bisexual above the empty basal scales, the uppermost often staminate with a rudimentary ovary; bristles 1- 6(-20), rudimentary, or absent; stamens 1—3(—12), the anthers elliptic to oblong; styles subulate, 2-branched or undivided. Achenes 2- sided to subcylindrical, sometimes inrolled with winged or wavy margins, obovate, oblong-obovate, or oblong-elliptic, deeply pitted, transversely rugulose, or smooth, the expanded, usually triangular style base persistent at the summit; bristles when present antrorsely or retrorsely barbed, sometimes smooth or feathery.
Distribution and Ecology - A genus of approximately 250 species, with its greatest diversity in the Western Hemisphere, particularly warm-temperate North America and the neotropics.
Genus Description - Perennials or sometimes annuals, vegetatively diverse; roots fibrous; culms cespitose or borne singly, 3-angled or obscurely so, sometimes channeled distally, occasionally cylindrical, smooth or sometimes scabrous distally, glabrous or sometimes hirsute. Leaves basal or basal and cauline; blades flattened or folded, sometimes inrolled, linear or filiform, herbaceous or occasionally stiff, glabrous, hirsute, or occasionally scabrous distally, rarely papillose, the margins and ventral midvein usually scabrous, ciliate, or with setose hairs; sheaths eligulate, rarely with a narrow band of trichomes, sometimes whitened at base, the inner band usually membranous, splitting with age. Inflorescence terminal or both terminal and lateral, paniculate, corymbose, or congested and headlike; involucral bracts leaflike, sometimes whitened at base; branches cylindrical, 3-angled, or subcompressed, ribbed, scabrous, ciliate, or smooth on margins; spikelets ovate, elliptic, or lanceolate, sometimes cylindrical or subcompressed, primarily 1- to several-flowered; scales spirally imbricate, ovate to lanceolate, finely nerved, with a single, distinct midrib, light to dark brown, sometimes whitish, the lower 2 to many, sterile. Flowers bisexual above the empty basal scales, the uppermost often staminate with a rudimentary ovary; bristles 1- 6(-20), rudimentary, or absent; stamens 1—3(—12), the anthers elliptic to oblong; styles subulate, 2-branched or undivided. Achenes 2- sided to subcylindrical, sometimes inrolled with winged or wavy margins, obovate, oblong-obovate, or oblong-elliptic, deeply pitted, transversely rugulose, or smooth, the expanded, usually triangular style base persistent at the summit; bristles when present antrorsely or retrorsely barbed, sometimes smooth or feathery.
Distribution and Ecology - A genus of approximately 250 species, with its greatest diversity in the Western Hemisphere, particularly warm-temperate North America and the neotropics.