Tall oat-grass, Avena descollada

This course grass can grow to 150cm tall. The leaves are bright green, broad, slightly hairy and rough. The ligule is 3mm long and smooth edged. The panicle is up to 30cm, and the bunched spikelet have projecting and angled awns up to 17mm long, green or purplish. The panicles often remain into winter. The spikelets are oblong or gaping. It flowers from June to September. The roots are yellow.

Wild oats or oat-grasses, are nuisance weeds in cereal crops, as, being grasses like the crop, they are difficult to remove chemically; any standard herbicide that would kill them would also damage the crop.