Thelepogon Syst. Veg. 2: 46 (1817).
Derivation:. From Greek thele (a wart) and pogon (beard), alluding to the rugose surface of the lower glume and the awned spikelets.
Taxonomic revisions, nomenclatural references:. B.K.Simon, Austrobaileya 4: 105–108 (1993).
Key references (keys and floras):. M.Lazarides, Tropical Grasses S.E.Asia 75–76 (1980); B.K.Simon, Key to Australian Grasses 168 (1993); D.Sharp and B.K.Simon, AusGrass (2002).
W.D.Clayton & S.A.Renvoize, Genera Graminum (1986), genus (598).
Native. 2 species, from tropical Africa, Asia to Australia. 1 species in Australia, Qld. Also Malesia.
Habit. Rather stout, erect or decumbent annual (often with prop roots), tufted. Leaf blades broad, cordate. Ligule an unfringed membrane or a fringed membrane.
Inflorescence. Inflorescence of spicate main branches (of long, brittle golden racemes), a single raceme or spike or a spike-like panicle, subdigitate (the racemes on a short common axis). Spikelet-bearing axes racemes (with numerous spikelets), clustered, disarticulating at joints. Internodes disarticulating transversely, somewhat hairy (i.e., the margins ciliate).
Spikelets. Spikelets dorsally compressed, 2 flowered, with 1 fertile floret, paired (but the pedicellate one reduced to the pedicel), sessile and pedicelled (the pedicelled component vestigial), in pedicelled/sessile combinations; sessile spikelet with lower incomplete floret. Fertile spikelets abaxial (with lower glume on side away from rachis), falling with glumes (deciduous with the joint and the sterile pedicel).
Glumes. Glumes more or less equal, exceeding florets, long relative to adjacent lemmas, hairless, glabrous, pointed, awnless, non-keeled (rounded on the back), dissimilar (both wingless, more or less rugose, the lower firmer). Lower glume convex on back, strongly rugose or muricate or tuberculate, 7–9 nerved. Upper glume 1 nerved (to 3?).
Florets. Lower incomplete floret(s) male. Lemmas awnless, 2 nerved, more or less equalling fertile lemmas, similar in texture to fertile lemmas (hyaline), not becoming indurated. Fertile florets 1. Lemmas less firm than glumes (hyaline), not becoming indurated, incised, deeply cleft, awned, without a germination flap, 3 nerved or 5 nerved, glabrous. Awns 1, from a sinus, geniculate, hairless (glabrous), much longer than body of lemma. Palea relatively long, entire, 2 nerved, not keeled. Callus short, blunt. Lodicules 2. Stamens 3. Grain small, ellipsoid, compressed dorsiventrally. Hilum short. Embryo large (about half the length of the fruit). Pedicels basally free of rachis (the pedicel and joint separated below, contiguous above). Pedicelled spikelets absent.
Kranz Anatomy. C4.
Habitat. Helophytic to mesophytic. Seasonally wet, heavy soils and disturbed ground. Species of open habitats.
Classification. Panicoideae; Andropogoneae.
Notes. Distinguished from Ischaemum mainly by the barren pedicel (Clayton & Renvoize, 1986).
Types Species. T. elegans Roem. & Schult.
Biogeographic Element. Clifford & Simon 1981, Simon & Jacobs 1990: Indo-Malayan.