17. AGROSTIS, Linn.
Annual or perennial grasses, of very various habit. Leaves usually flat, sometimes setaceous, often flaccid; ligules membranous. Spikelets small, 1-flowered, arranged in effuse or contracted panicles with capillary whorled branches; rhachilla disarticulating above the 2 outer glumes, not produced beyond the flower. Glumes 3; 2 outer equal or subequal, empty, keeled, acute, not awned, usually 1-nerved; 3rd or flowering glume membranous or hyaline, glabrous or hairy, usually truncate, 5-nerved or rarely 3-nerved, with a dorsal awn or unawned, callus glabrous or with a few minute hairs. Palea usually short, often minute or wanting, thin and delicate, hyaline, 2-nerved or nerveless. Lodicules 2. Stamens 3. Styles very short, distinct; stigmas plumose. Grain oblong, free within the flowering glume.
Species about 100, found in all parts of the world, but most abundant in temperate regions, and penetrating as far into the arctic and antarctic zones as any other grasses. Of the 7 species admitted in this work, one is generally distributed in high southern latitudes, two or possibly three are found in Australia, the remainder are endemic.
| *Awn of flowering glume distinctly exserted beyond the empty glumes. | |
| Culms 3–18 in. Panicle contracted, 1–4 in. Spikelets ⅙ in. long; pedicels almost hispid | 1. A. magellanica. |
| ** Awn of flowering glume often wanting; when present not exceeding the empty glumes. | |
| Minute, softly pulvinate, seldom more than 1 in. high. Panicle usually sunk among the leaves | 2. A. muscosa. |
| Slender, strict, densely tufted, 2–9 in. Panicle narrow, almost spike-like, ½–2 in. long | 3. A. Muelleri. |
| Tufted, 4–18 in.; innovation-shoots intravaginal, without leafless scales at the base. Panicle 2–5 in., contracted, rather dense; branches numerous. Spikelets 110–18 in., empty glumes scabrid on the keel | 4. A. Dyeri. |
| Laxly tufted, 6–18 in.; innovation-shoots extravaginal, with leafless scales at the base. Panicle 2–6 in., lax; branches in whorls of 3–5. Spikelets ⅙ in., empty glumes smooth | 5. A. Petriei. |
| Weak, very slender, 6–18 in. Panicle 2–6 in., lax and spreading; branches few, capillary, trichotomously divided. Spikelets minute, 115, in. | 6. A. parviflora. |
| Laxly tufted, very slender, 6–15 in. Panicle linear, 1½–4 in. by 110–16 in.; branches short, erect. Spikelets 112–110 in., pale, shining | 7. A. tenella. |
Two common European species, A. vulgaris (Red-top) and A. alba (Fiorin), are copiously naturalised in most parts of the colony. They come nearer to A. Dyeri than to any other of the indigenous species, but differ in the creeping rootstocks, laxer panicles, and in the florets having a well-developed palea. Descriptions of them will be found in any British Flora.
1. A. magellanica, Lam. Ill. i. 160.—Culms tufted, very variable in size, 3–18 in. high, erect or shortly decumbent at the base,
