Plants annual. Culms
5-40 cm, erect or ascending. Sheaths
glabrous or pubescent; ligules
1.2-2.6 mm, puberulent, obtuse, laciniate; blades
2-15 cm long, 2-5 mm wide, pubescent on both surfaces. Panicles 2-12 cm long, 1-5 cm wide, dense, ovoid, stiffly erect,
sometimes racemose; branches shorter
than the spikelets, ascending, slightly curved or straight. Spikelets 10-40(45) mm long, 4-10 mm
wide, lanceolate to elliptic or oblong, laterally compressed; florets 5-8(10), bases concealed at
maturity; rachilla internodes
concealed at maturity. Glumes
glabrous or pubescent; lower glumes
5-8.5 mm, 3-5-veined, lanceolate; upper
glumes 6.5-9.5 mm, 7-9(11)-veined, elliptic; lemmas 8-12(13.5) mm long, 6-7 mm wide, oblanceolate, veins
glabrous, scabridulous, or ciliolate, glabrous or pubescent elsewhere,
9-11-veined, rounded over the midvein, margins broadly hyaline, bluntly angled
above the middle, not inrolled at maturity, apices subulate to acute or obtuse,
toothed, teeth shorter than 1 mm; awns
usually 3 on the upper lemmas in each spikelet, arising 2-4 mm below the lemma
apices, purple or deep red, central awn 5-25 mm, flattened at the base,
divaricate and sometimes twisted at maturity, lateral awns 4-10 mm, erect or
reflexed, sometimes absent or much reduced on the lower lemmas; anthers 1-1.8 mm. Caryopses equaling or shorter than the paleas, thin, weakly
inrolled or flat. 2n = 14.
Bromus danthoniae is native from the western Asia to southern
Russia and Tibet. It was collected in 1904 in Ontario; no other North American
collections are known.