Zerna tectorum (Linn.) Panzer ex Jacks.
Annual; culms erect, up to 60 cm high. Leaf-blades up to 18 cm long, 2-4 mm wide; sheaths pubescent. Panicle up to 18 cm long, loose or dense, erect or nodding, the branches filiform, flexuous, bearing parallel clusters of spikelets, these usually all turned to one side. Spikelets narrowly wedge-shaped, very fragile, 4-8(-10)-flowered, the upper 1-3 florets sometimes much reduced or aborted, 25-40 mm long including the awns, the lemmas overlapping at first but gaping and exposing the internodes at maturity; glumes with silvery-hyaline margins, the lower narrowly lanceolate, 5-8 mm long, 1-nerved, the upper narrowly oblong-lanceolate, 7-11 mm long, 3-nerved; lemmas linear-lanceolate in side view, the lowest 9-14 mm long, involute, herbaceous with silvery-hyaline margins, 7-nerved, glabrous or pubescent, 2-toothed at the tip with a straight awn as long as or slightly longer than the lemma from between the teeth; palea shorter than the lemma, ciliolate on the keels; anthers 0.5-1 mm long.
Fl. & Fr. Per. : March-May in the south, June-July in Kashmir.
Type locality: Europe.
Distribution: Pakistan (Baluchistan, N.W.F.P., Gilgit & Kashmir); Central Europe and the Mediterranean region; throughout the Middle East to the western Himalayas; Central Asia, Siberia and China; North Africa and Macaronesia.
Gregarious in waste places and deserts, in walls and on roofs (tectorum = of roofs).