Family: Poaceae |
Mary E. Barkworth Plants annnual or perennial. Leaves never aromatic; ligules membranous. Inflorescences paniculate, of 2 or more rounds of aggegration of pairs of pedunculate pairs of rames; rames with up to 2 of the basal sessile-pedicellate spikelet pairs male or sterile, unawned and tardily deciduous; branch internodes and pedicels linear; sessile spikelets narrowly lanceolate to lanceolate-oblong, dorsally compressed or terete; calluses obtuse to strongly pointed, attached obliquely to the top of the subtending internodes; lower glumes coriaceous, broadly convex, without keels or keeled only in the upper third; upper glumes unawned; lower florets reduced to hylaline lemmas; upper lemmas stipelike, 2-toothed, awned, awns stout; pedicellate spikelets male or sterile, narrowly lanceolate, usually a little longer than the sessile spikelets, unawned or aristulate from the lower glumes. Caryopses oblong, subterete. Hyparrhenia is a genus of 56 species. They grow in tropical regions throughout the world. Only two species are known from Somaliland and Somalia. Key to the species of Hyparrhenia in Somaliland and Somalia. Plants annual or perennial; cespitose, often with short rhizomes. Culms 30-350(400) cm, usually erect, much branched above the bases. Leaves not aromatic; ligules membranous, not ciliate; blades usually flat or folded. Inflorescences false panicles with numerous inflorescence units; peduncles with 2 rames in digitate clusters; rames with naked, often deflexed bases, axes without a translucent median groove; disarticulationin the rames, beneath the bisexual spikelets. Spikelets in sessile-pedicellate pairs, basal 1-2 pairs on each rame homogamous, morphologically similar to the heterogamous pairs, staminate or sterile, unawned, not forming an involucre, tardily deciduous, remaining pairs heterogamous. Heterogamous spikelet units: sessile spikelets dorsally compressed or subterete; callusesblunt to sharp, strigose; glumes equal, pubescent; lower glumescoriaceous, rounded, without keels, truncate to slightly bilobed; upper glumes narrower, shallowly keeled; lower florets sterile, reduced; upper florets bisexual, awned from between the teeth of the bifid lemma; awns usually present, to 3.5(19) cm, pubescent on the lower portion. Caryopses oblong, subterete. Pedicels slender, not adnate to the rame axes. Pedicellate spikelets usually slightly longer than the sessile spikelets, staminate or sterile, usually unawned, lower glumes sometimes aristulate. x = 10, 15. Name from the Greek hypo, under, and arrhen, masculine, referring to the pair of staminate spikelets at the base of the rames of some species. Global distribution of Hyparrhenia. Note: GBIF records include introduced and cultivated plants. Consequently, the distribution shown often differs from statements about a taxon's native distribution. |