Family: Poaceae |
Christopher S. Campbell Plants perennial; usually cespitose, sometimes rhizomatous. Culms20-310 cm, erect, much-branched distally. Leaves not aromatic; ligules membranous, sometimes ciliate; blades linear, flat, folded, or convolute. Inflorescences terminal and axillary or a false panicle; inflorescence units 1-600+ per culm; peduncles initially concealed by the subtending leaf sheaths, sometimes exserted beyond the sheaths at maturity, with (1)2-5(13) rames; rames not reflexed at maturity, axes slender, terete to flattened, not longitudinally grooved, usually conspicuously pubescent, with spikelets in heterogamous sessile-pedicellate pairs (the terminal spikelets sometimes in triplets of 1 sessile and 2 pedicellate spikelets), apices of the internodes neither cupulate nor fimbriate; disarticulation in the rames, below the sessile spikelets. Sessile spikelets bisexual, awned, with short, blunt calluses; lower glumes 2-keeled, flat or concave, usually not veined between the keels, sometimes 2-9-veined; anthers 1, 3(2). Pedicelsusually longer than 3 mm, similar to the rame internodes in shape, length, and pubescence color, not fused to the rame axes. Pedicellate spikelets usually vestigial or absent, sometimes well-developed and staminate. x = 10. Name from the Greek andro, man, and pogon, beard, referring to the pubescent pedicels of the staminate spikelets. Cope, T.A. Poaceae (1995) Flora of Somalia 4: 149-270 Plants annual or pereenal. Leaves not aromatic; ligules membranous or a line of hairs. Inflorescences usually composed of paired or digitate spikelike branches of sessile-pedicellate spikelet pairs or triplets that disarticulate below the sessile spikelet, axillary inflorescence branch clusters often subtended by a leafy bract, formining a complex, leaf infloresence; inflorescence branches terete, rarely reflexed at maturity, without morphologically distinct homogamous spikelet pairs at the base. Sessile spikelets dorsally or laterally compressed; caluses obtuse, inserted in the concave top of the internode; lower glumes membranous to coriaceous, flat to concaveor deeply grooved on the back, 2-keeled, the keels lateral or dorsal, sometimes narrowly winged, vins prsent or absent between them; lower floretes sterile, reduced to hyaline lemmas; upper lemmas hylaine, bilobed, usualy awned from between the lobes, rarely entire and unawned; caryopses narrowly lanceolate to oblong, subterete to planoconvex. Pedicellate spikelets male or sterile, rarely completely suppressed, never concave on the back, usually unawned. Andropogon includes about 100 species, all native to tropical regions. Key to the species of Andropogon in Somaliland and Somalia. |