≡ _Leaves flattened. Panicle somewhat close. Often tall grasses._ _z Meadow-grass, with 5-6 to a dozen or more flowers in the spikelet._ _F. elatior_, L. _zz Shade-grass, with 4-5 flowers only in the spikelet._ _F. sylvatica_, Vill. ≡≡ _Leaves subulate or setaceous, at least below. Mountain pasture grass, usually small._ _F. ovina._ Concerning difficulties between _Poa_ and the awnless forms of _Festuca_, see p. 114. _F. elatior_ and _F. sylvatica_ are practically awnless, the awn-points being merely the acuminate tips of the paleæ. The long-awned species of _Festuca_ have compact stiff panicles and narrow or setaceous leaves (see p. 111). Regarding varieties of _F. ovina_, see p. 112. †† Awns, twisted below and bent above, inserted into the middle of the back of the bifid palea or below it. ⊙ _Awns long and conspicuously projecting from the spikelet, which is gaping and contains 3-5 flowers. Leaves flat._ +Avena.+ ≡ _Tall annual corn-weed, with large (18-20 mm.) heavy, pendent, hairy spikelets on the long slender stalks of the lax open panicle. Leaves glabrous._ _A. fatua_, L. This is the so-called Wild Oat, and the type of this group. ≡≡ _Tufted perennials with spikelets more or less erect on stiffer stalks, the panicle therefore less open._ _z Panicle nearly simple; spikelets silvery or reddish, 12-15 mm. long._ _A. pratensis_, L. _zz Panicle branched but not very open; spikelets glistening yellow and only 5-6 mm. long._ _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._