1	"Awns 4-6 cm long"	"Bromus diandrus"
1	"Awns up to 3 cm long or absent"	2
2	"Awn arising from back of lemma 3/4 way from base"	"Bromus alopecuros"
2	"Awn arising at or near lemma apex"	3
3	"Lemmas laterally compressed and sharply keeled"	"Bromus catharticus"
3	"Lemmas not compressed, rounded on back"	4
4	"Lower glume 3-7-nerved; upper glume 5-9-nerved"	"Bromus hordeaceus"
4	"Lower glume usually 1-nerved; upper glume 1-3-nerved"	5
5	"Inflorescence open and loose"	"Bromus arenarius"
5	"Inflorescence contracted"	6
6	"Inflorescence very dense; lemma teeth 2-4 mm long"	"Bromus rubens"
6	"Inflorescence moderately dense; lemma teeth 1-2 mm long"	"Bromus madritensis"