Syntherisma fusca (Presl) Scribner
Annual; culms 20-60 cm high, erect or geniculately ascending, seldom stoloniferous. Leaf-blades 3-25 cm long, 2-7 mm wide. Inflorescence composed of (2-) 3-6(-9) subdigitate racemes; racemes 3-14 cm long, the spikelets ternate on a ribbon-like winged rhachis with low rounded midrib; pedicels terete to ± flattened and winged, scabrid, with discoid or cupuliform tip. Spikelets elliptic, 1.2-2 mm long; lower glume an obscure hyaline rim; upper glume four-fifths to almost as long as the spikelet, 3(-5)-nerved, with, short appressed verrucose hairs between the nerves; lower lemma as long as the spikelet, 5-7-nerved, pubescent (often obscurely so) with verrucose hairs; fruit ellipsoid, dark brown to almost black.
Fl. & Fr. Per: (May-) July-August.
Type: Cult. at Berlin, seed from Brazil (B).
Distribution: Pakistan (Punjab, N.W.F.P. & Gilgit); tropical Asia and America; introduced and naturalised in Tanzania.
Digitaria violascens is closely allied to Digitaria longiflora. The two species intergrade to some extent, and there are no infallible characters for separating them. Typically Digitaria violascens is a more erect plant with 3 or more slender racemes, scabrid pedicels, a smaller upper glume (commonly 3-nerved and noticeably shorter than the spikelet) and a dark-coloured fruit.