Phleum pratense, L. (Timothy-grass). No stolons, but bulbous on dry ground. Early, and a heavy cropping hay grass: also excellent pasture; branches intra-vaginal, but burst the glabrous sheaths. Old sheaths fibrous. Leaves short, convolute, with scabrid margins owing to deflexed teeth: ridges obsolete above, no keel; broader and greyer green than Alopecurus. Ligule short on radical leaves, thin. Pastures. Perennial.
The smooth ligule, deflexed marginal teeth, and no keel distinguish it from Arrhenatherum.
Phleum arenarium, L. (Sand Phleum). Shoot annual, with no bulbs. Leaves broad, flat and glabrous, but rough at the edges, with descending teeth. Ridges low and flat. Sheaths smooth: leaves conduplicate. Ligule long. Sandy coasts, &c. A weed.
Phleum asperum, Jacq. and P. Bœhmeri, Schrad. are rare ruderal plants, and P. alpinum, L. is confined to the Scotch Highlands. P. arenarium is sharply distinct by its conduplicate leaves and habitat.
Alopecurus pratensis has narrower and less grey-green leaves than Phleum pratense, its ligule is shorter and blunter, its sheath more grooved and dark below, and the ridges more distinct and flat. It is relatively well rooted and is stoloniferous.
Arrhenatherum avenaceum, Beauv. (False Oat-grass). Loose tufts with short stolons, or bulbous below. Leaves few, narrow, thin, dry, rough, with very low flat ribs, convolute in bud, and practically glabrous. Sheath smooth. Ligule truncate, hairy on its outer surface. Bitter, and commonly undervalued by agriculturists, but useful in mixed pasture, and yields bulky, coarse hay.
There are often a few sparse isolated hairs on the low ribs. The base enters the sheath with slight and sometimes pinkish ledges. Ridges hardly observable. Traces of roughness if rubbed downwards. White lines, about 5 each side on holding up to the light. The not very long leaves taper slightly below.
Arrhenatherum is liable to confusion with Holcus, Anthoxanthum, Molinia and Avena, but it is typically glabrous, whereas the others are hairy.
From Holcus it is easily distinguished by the sheaths, ligule and soft hairs of that genus.
Anthoxanthum differs in its habit, ears, scent, sheath and ligule.
Molinia differs in habit, ligule, sheath, and tough stringy roots, and the shape of the leaves.
Avena pratensis differs in its narrow leaves, less prominent ridges, and ligule; A. flavescens in its much broader and coarser hairy leaves, and the ligule; and A. pubescens in pubescence and flat-shoots and ligule.
†† Leaves very thin, blade tapering below. Keel prominent, but no ridges above. Ligule long and torn.
Milium effusum, L. (Spreading Millet-grass). Tufted perennial. Leaves linear-lanceolate, scabrid above. Sheath smooth. Bitter tasting. May be slightly hairy. Woods. It is much liked by birds, but is of no value in agriculture.
B. Leaves or sheaths, or both, distinctly hairy.
(α) Leaf-blades eared at the base.
(a) Ears sharply pointed. Leaves convolute, and sections of shoots round. Ligule short and inconspicuous.
Agropyrum repens, Beauv. (Couch-grass). A troublesome weed of arable land and gardens, &c., owing to the extraordinary vitality of its underground stolons. The young shoots are readily eaten by stock. Perennial, and extensively stoloniferous; bright or glaucous green. Blade thin, dry, rough edged, hairy and rough above, glabrous or hairy below. The short ligule fringed. Ears long, or sometimes short, pointed; often obliquely crossing in front of the sheath. Ridges inconspicuous. Hairs may be absent from the sheath, and nearly so from the blade.