Tricholaena wightii Nees & Arn. ex Steud.
Annual or loosely tufted perennial; culms 30-100 cm high, erect or ascending. Leaf-blades flat or folded, 5-30cm long, 2-10mm wide. Panicle ovate, 5-20cm long, fluffy, silvery pink or purple; pedicels usually pilose at the tip. Spikelets ovate, 2.5-8.5 mm long, villous with hairs extending 1-4mm beyond the tip; lower glume narrowly oblong, 0.3-0.5mm long, separated from the upper by an internode 0.1-1.2mm long; upper glume conspicuously gibbous, chartaceous, tapering to a glabrous membranous beak a quarter to half its length, emarginate, mucronate or with an inconspicuous awn up to 7 mm long; lower floret male or barren, its lemma narrower and less gibous than the upper glume, its palea ciliate on the keels.
Fl. & Fr. Per.: August-September.
Type: Guinea (Ghana), Isert (B).
Distribution: Pakistan (Punjab, introduced); throughout Africa; introduced to most other tropical countries.
Rhynchelytrum repens is a polymorphic species with considerable variation in the size, indumentum and colouring of the spikelets, and in the habit of the plant. It is customarily divided according to whether there is a long (Rhynchelytrum villosum) or short internode between the glumes. In fact the length of this internode (and also that of the lower glume) varies continuously, and is found to be directly proportional to the length of the spikelet.