| | 1. Awns short-hairy below midpoint |
| A. sterilis |
| | 1' Awns glabrous to minutely scabrous |
| |
| | 2. Forks at lemma tip bristly, bristles > 2 mm |
| |
| | 3. Lemma generally soft-hairy below awn; spikelet breaking at maturity |
| A. barbata |
| | 3' Lemma ± glabrous to soft-hairy at base; spikelet axis not breaking at maturity |
| A. strigosa |
| | 2' Forks at lemma tip < 1 mm or 0 |
| |
| | 4. Upper and lower floret awns generally subequal, awn bent, twisted below bend |
| A. fatua |
| | 4' Upper floret awn << lower floret awn or 0, awn generally straight, slightly twisted |
| A. sativa
|