Slender Oat

Avena barbata subsp. wiestii (Steud.) Mansf. has been reported from Pakistan, but its presence cannot be fonfirmed. Several authors (e.g. Bor, l.c.) distinguish it from subsp. barbata by the presence of a lateral tooth at the base of each bristle at the tip of the lemma, a character which is unreliable. They are best distinguished by spikelet length (16-20 mm in subsp. wiestii., 20-30 mm in subsp. barbata) and length of the lowest lemma (12-16 mm and 16-20 mm respectively). Subsp. wiestii also has a larger, more floriferous panicle.

Annual; culms 30-100 cm high, erect or ascending, slender to rather stout, simple. Leaf-blades up to 30 cm long, 3-8 mm wide, sparsely hairy to ciliate; ligules 2-5 mm long. Panicle subsecund, up to 30(-50) cm long and 12 cm wide, loose with smooth or faintly scaberulous branches. Spikelets 18-30 mm long, 2-3-flowered, the rhachilla articulated beneath each floret; glumes lanceolate, acuminate; lemmas 12-20 mm long, densely bearded with hairs up to 3 mm long around the callus, densely hairy with long stiff hairs up to the insertion of the awn, scabrid or asperulous on the nerves above, narrowed upwards and finely 2-toothed at the apex, the teeth aristulate with bristles 3-12 mm long; awn 3-6 cm long, geniculate, the column usually darker than the bristle, glabrous to faintly asperulous.

Distribution: Pakistan (Baluchistan & N.W.F.P.); southern Europe and the Mediterranean eastwards to Nepal and southern USSR.

Fl. & Fr. Per.: February-May.