1	Annual; spikelets laterally compressed; anthers 0.5–1 mm.		1 B. distachyon
+	Perennial; spikelets subterete; anthers 3–5 mm		(2)
2 (1)	Raceme with 1–3 spikelets; culms 10–30 cm tall; leaf blades needle-like.		2 B. kawakamii
+	Raceme with 3–6(–15) spikelets; culms usually more than 30 cm tall; leaf blades linear		(3)
3 (2)	Lemmas of all florets with 1–6 mm awn; plant with spreading rhizomes.		3 B. pinnatum
+	Lemmas of upper florets with 5–14 mm awn; plant without rhizomes		(4)
4 (3)	Pedicels of spikelets less than 2 mm.		4 B. sylvaticum
+	Pedicels of spikelets 2–5.5 mm.		5 B. pratense