A. flavescens, L.
There is no other genus closely resembling Avena. The superficial likeness of some Bromes disappears at once on examination. The spikelets of Aira are much smaller, and the leaves quite different (see below and p. [47]).
⊙⊙ Awns fine and hair-like and not conspicuously protruding from the spikelets; the latter small, 2-5 mm. Flowers two in each spikelet.
Aira.
≡ Coarse and tall tufted grass with flattened, harsh, and conspicuously ribbed leaves: the very short awns hardly protruding.
A. cæspitosa, L.
No other grass can be confused with this if the very high ridges of the leaves are observed (see p. [47]).
≡ ≡ Small grasses with setaceous or very narrow inrolled leaves. Awns slightly protruding.
x Palea distinctly bifid at the apex: awn nearly twice its length. A very small grass about six inches high: leaves subulate, fine and short.