The rare C. echinatus has the pectinate groups of barren glumes even more prominent.
✲✲ Stout glaucous sand-binder with pairs of spikelets sessile in the notches of the rachis, and all fertile. Spike cylindrical. Not common.
Elymus arenarius, L.
For other sand-binders see p. [102]. The only grass likely to be confounded is Agropyrum, in which the spikelets are not paired. Lolium, Brachypodium, &c. are easily distinguished.
(ii) Spike short and ovoid: spikelets sub-sessile and imbricate, in clusters. Bluish.
Sesleria cærulea, Ard.
Not easily mistaken for any other grass. As some of the spikelets are shortly stalked, the inflorescence is strictly paniculate, but the fact is not obvious. The glume-like bract at the base of the spike, and the general appearance suggest resemblances to certain moor-sedges at first sight. The only other grasses with similarly shaped spikes are species of Alopecurus, Phleum, and the rare Lagurus, Polypogon, Phalaris, Panicum, all with very different spikelets and easily distinguished.
(2) Inflorescence a panicle or raceme—i.e. the spikelets on evident stalks, simple or branched, from the main axis.
It does not follow that every spikelet is distinctly stalked, and cases occur where the stalks are very short and stiff: when this happens to the stalks arising from the main axis, and the latter is elongated, the type of the spike is closely approached, and the inflorescence resembles that of Brachypodium, Lolium, &c. In some depauperated varieties of Poa, Festuca, &c., an actual spike results (see note, p. [111]): the number of flowers in the spikelet is important.
(a) Panicle short, contracted and tuft-like, owing to the shortness and stiffness of most of the stalks and their tendency to remain erect, at least until anthesis. Glumes keeled and ending in a point.
(i) Panicle with a few branches, at first erect, ending in tuft-like secund clusters. Spikelets harsh, with 3-5 flowers. Coarse meadow-grass.