Downy Brome
Bromus tectorum

Description: This non-native grass is a winter or spring annual of variable size. On dry barren ground, it is typically ¾–1½' tall, while on moist fertile ground it can become 2-3' tall. Individual plants are tufted at the base, sending up multiple unbranched culms. These culms are terete, green, and very finely pubescent (canescent); they are largely hidden by the sheaths. The blades of the leaves are up to 4" long and 1/3" (8 mm.) across; they are whitish green and pubescent on both the upper and lower sides. The sheaths of the leaves are whitish to reddish green, densely pubescent, and longitudinally veined. Each culm terminates in a panicle of spikelets about 2-6" long. Both the central stalk (or rachis) and branches of this panicle are strongly inclined to droop. An immature panicle is barely exerted from the sheath of the uppermostImmature Inflorescence leaf, while a mature panicle is more exerted and more widely spreading. The individual spikelets are about ¾–1½" long (including their awns). They are whitish to reddish green and frequently shiny in appearance. Each spikelet consists of a pair of glumes and 5-9 lemmas that are arranged in two ranks. These lemmas are appressed together in young spikelets, but they become more widely spreading in older spikelets. The first glume is 5-7 mm. long, linear, and glabrous to finely pubescent; it has a single prominent vein. The second glume is 8-10 mm. long, linear, and glabrous to finely pubescent; it has 1-3 prominent veins. The lemmas are 10-12 mm. long (excluding their awns), linear-lanceolate, and finely pubescent to hairy (rarely glabrous); they have 5-7 veins that are more difficult to discern. The slender awns of the lemmas are about 12-16 mm. long and more or less straight. The blooming period occurs from mid-spring to early summer. Shortly afterwards, the entire plant becomes light tan. Disarticulation of the spikelets is above the glumes. Each awned lemma encloses a single grain that is long and slender. The root system is fibrous. This grass species spreads by reseeding itself. Colonies of plants are often formed at favorable sites.