Again, _Agrostis alba_ has no protruding awn, as in the spikelets of _Aira_. For _Aira cæspitosa_ and other details, see p. 117. * _Awnless, or at most a short bristle not equalling the palea. Leaves flat and short._ _A. alba_, L. An exceedingly variable plant. The variety _A. stolonifera_ has a less spreading panicle, and broader leaves with a long serrated and pointed ligule: the variety _A. vulgaris_ has a spreading loose panicle, narrower leaves, and a short truncated ligule. There is, however, much difficulty in distinguishing the intermediate forms on mountain-pastures, &c. ** _Distinctly awned. Leaves narrower, the lower ones inrolled and almost setaceous._ _A. canina_, L. The rarer _A. setacea_, Curt. with subulate leaves and _A. Spicaenti_, L. with long awns also come here. The lax spreading type of panicle characteristic of _Aira_ and _Agrostis_, &c., described above, occurs in species of _Avena_, _Bromus_, _Briza_, _Poa_ and _Catabrosa_, but the basal silky hairs and twisted awns (_Avena_), long sub-terminal bristle-awns (_Bromus_), habit (_Catabrosa_), and the presence of two, three, or more flowers in the considerably larger spikelets of all, easily distinguish them. The rare grasses _Leersia_, with two glumes and no paleæ, and _Gastridium_, with curiously bullate bases to the glumes, also come into this group with one-flowered spikelets, but their characters must be studied with the flora. The same remark applies to species of _Panicum_, _Cynodon_, _Spartina_ and other aliens, occasionally met with. II. GRASSES WITH AT LEAST TWO FLOWERS--OF WHICH ONE MAY BE IMPERFECT--IN THE SPIKELET. +A. Only one perfect flower, the other staminate only or altogether rudimentary. Inflorescence a loose or racemous panicle.+ In _Hordeum sylvaticum_ the two lateral spikelets occasionally conform to this heading (see p. 100), and the same is said to be the case sometimes in _Aira_ (see p. 104). The rudiments are extremely minute, however, and hardly suffice to justify the removal of these grasses to this group. In one or two species of _Aira_ the panicle may be somewhat contracted and tuft-like. The very rare _Hierochloe_ has one perfect flower, and two lower staminate ones in each spikelet. (_a_) A shade-grass found in woods. Awnless. One flower perfect, the other (upper) reduced to a small stalked knob. Inflorescence racemous. _Melica uniflora_, L. The much rarer _M. nutans_ has two perfect flowers and a similar rudiment (see note, p. 104). (_b_) Grasses of open situations, spikelets with awns. The reduced flower staminate. * Upper flower perfect, lower staminate only. Tall oat-like meadow-grass, with a bent and twisted dorsal awn to the outer palea of the lower flower: silky hairs at the base of paleæ.