1b. var. sativa (L.) Hausskn. (oats)
A. sativa L.
Spikelets with 2(3) florets, disarticulating above the
glumes at maturity. Florets awnless or the lowermost floret with the lemma
awned, the awn 15–35 mm long, straight or somewhat curved, but not bent or
twisted, the lemmas glabrous or somewhat roughened, sometimes with a few hairs
3–5 mm long at the base. Fruits 7–12 mm long. 2n=42. May–November.
Introduced, widely scattered nearly throughout Missouri (cultigen of Eurasian origin; cultivated nearly worldwide in temperate regions).
Roadsides, railroads, fallow fields, gardens, and open, disturbed areas.