Description :

• Perennial, tufted, tall, sometimes shortly rhizomatous
• Leaf blade linear; ligule an unfringed to a fringed membrane
• Inflorescence a terminal panicle, narrow, loose to somewhat dense, branches filiform, primary branches appearing whorled, divided almost from base into flexuous peduncles bearing fragile racemes (sometimes these reduced to a single sessile spikelet), internodes and pedicels filiform, hairy, spikelets paired, appearing solitary since pedicelled spikelet usually reduced to a pedicel, pedicel free from rachis
• Sessile spikelet dorsiventrally compressed, plump; glumes ± equal, dissimilar, awnless; lower glume dorsiventrally compressed, flat or rounded on back, truncate, keeled only on tip, 9-nerved, often hairy on back; upper glume broadly convex on back, glabrous, slightly keeled above, 5-nerved
• Florets 2; lower floret sterile, reduced to a hyaline lemma, 2-keeled, margins inflexed, hairy, 2-nerved, awnless; upper floret bisexual; lemma less firm than glumes, hyaline, almost reduced to awn, 2-lobed, awned from sinus of lobes; awn long; callus obtuse to pungent, usually not conspicuously hairy; palea delicate, hyaline, lanceolate
• Lodicules 2, cuneate, fleshy, glabrous
• Stamens 3
• Ovary ellipsoid, glabrous; styles plumose
• Caryopsis oblong

• Pedicelled spikelet reduced to a filiform, hairy, barren pedicel somewhat shorter than sessile spikelet, occasionally with a spikelet similar to a sessile spikelet on same inflorescence
• x = 10 (polyploidy)

Nomenclature:

• Sorghastrum Nash
  • Nash: 71 (1901)
  • Chippindall: 463 (1955)
  • Clayton & Renvoize: 731 (1982)
  • Clayton & Renvoize: 341 (1986)
  • Gibbs Russell et al.: 300 (1990)
  • Watson & Dallwitz: 882 (1994)

Distribution & Notes:

• Global : Species ± 20, mainly tropical and subtropical America and Africa
• Southern Africa : Species 2, N Namibia and N Botswana, northern provinces of South Africa to Swaziland and N KwaZulu-Natal