Digitaria stewartiana Bor

This seldom collected species is allied to Digitaria ischaemum, but differs in its glabrous spikelets and delicate, rounded upper glume. It may prove to be a high-altitude variant of D. ischaemum when better known.

This species is used for forage.

This is very similar to Digitaria ischaemum, Digitaria longiflora and Digitaria violascens in having ternate spikelets, but the spikelets are quite glabrous. It seems to be related to Digitaria violascens in much the same way as Digitaria fuscescens is to Digitaria longiflora in that it lacks hair on the spikelets, but the delicate, translucent upper glume with a broad blunt tip distinguishes it better from Digitaria violascens than the simple hairy versus glabrous distinction drawn between Digitaria longiflora and Digitaria fuscescens. Digitaria stewartiana is known only from three collections from Kashmir.

Annual. Culms tufted, slender, decumbent at base, ascending, 15–30 cm tall. Leaf sheaths glabrous; leaf blades up to 6 × 0.5 cm, glabrous, base subrounded, margins scabrous, apex acuminate; ligule 1–1.5 mm. Inflorescence subdigitate; racemes 2–3, 4–5 cm; spikelets ternate; rachis ribbonlike, broadly winged, midrib triquetrous; pedicels terete, scabrous, tips cupuliform. Spikelets elliptic, 1.8–2 mm, glabrous; lower glume usually absent; upper glume ca. 4/5 as long as spikelet, hyaline, translucent, glabrous, 3-veined, broadly obtuse; lower lemma purplish, as long as spikelet, 5-veined with 3 central veins close together and outer 2 marginal, veins connected at tip; upper lemma purplish brown at maturity. Anthers ca. 0.5 mm. Fl. and fr. summer–autumn.

Annual; culms up to 30 cm high, geniculately ascending. Leaf-blades up to 6 cm long and 5 mm wide. Inflorescence composed of 2-3 subdigitate racemes; racemes up to 5 cm long, the spikelets ternate on a ribbon-like winged rhachis with triquetrous midrib; pedicels ± terete, scabrid, with cupuliform tip. Spikelets elliptic, 1.8-2 mm long; lower glume 0; upper glume about four-fifths as long as the spikelet, 3-nerved, the nerves anastomosing below the apex, glabrous; lower lemma as long as the spikelet, 5-nerved, the middle 3 nerves close together and parallel, the outer pair marginal, glabrous; fruit ellipsoid, dark purple-brown at maturity.

Xinjiang, Xizang [Kashmir].

Distribution: Kashmir, endemic.

Fl. & Fr. Per.: August-September.

Mountains; 2000–3000 m.

Digitaria ischaemum (Schreber) Muhlenberg subsp. ste-wartiana (Bor) Tzvelev.