105. C. alopecoídea, Tuckerm. Stout but rather soft, 2–3° high; culm rather sharp, thick and soft in texture; leaves 2–3´´ wide, about the length of the culm, very green; head 1½´ long or less, sometimes green, and occasionally a little compound, the spikes many and compactly or somewhat loosely disposed or the lowest often separate and all mostly short-oblong; perigynium ovate, tapering into a rough beak, very prominently stipitate, with a few brown nerves on the outer face, ascending, about equalling or a little exceeding the scale.—Open swales, N. Y., Penn., and Mich.; local. In aspect like n. 101.
Var. sparsispicàta, Dewey. Weak, the leaves much narrower and lax; head 1–3´ long and linear or nearly so, the spikes smaller and separated or scattered.—S. E. Mich. (Cooley, Clark); little known.
106. C. grávida, Bailey. Lower and the culm thinner and more sharply angled, 1–2° high; leaves rather narrower and firmer, shorter than the culm; head short, always simple, globular or short-oblong, the lowest spikes rarely distinct; spikes few (4–7), globular, or broader than long; perigynium broadly ovate, nearly twice larger, sessile, plump and somewhat polished at maturity, prominently spreading.—N. Ill. to Iowa and Neb.—Var. laxifòlia, Bailey. Much larger, 2–3½° high; leaves broader (about ¼´) and lax; head large and dense, ovoid or oblong, scarcely interrupted. N. Ill. to Dak.
2. Perigynium very small, mostly nerved on the inner face.
107. C. vulpinoídea, Michx. Mostly rather stiff, 1–2½° high; culm very rough, at least above; leaves various, mostly flat and longer than the culm; head 1–4´ long, usually much interrupted and frequently somewhat compound, varying from dull brown to almost green at maturity, commonly provided with many very setaceous short bracts; spikes very numerous, ascending and densely flowered; perigynium ovate or lance-ovate, mostly ascending.—Low places, variable; very abundant, especially northward.
b. Scales blunt, smooth and hyaline-tipped.
108. C. Sartwéllii, Dewey. Stiff and strict, 1½–2½° high; leaves produced into a long slender point, mostly shorter than the culm; staminate flowers variously disposed, frequently whole spikes being sterile; head 1–3´ long and rather narrow, the individual spikes usually clearly defined, or occasionally the head interrupted below, tawny-brown; perigynium elliptic or lance-elliptic, nerved on both sides, very gradually contracted into a short beak; scale about the length of the perigynium. (C. disticha, last ed.)—Bogs, central N. Y., west and northward; frequent.
C. arenària, Linn. Extensively creeping, 1° high or less; leaves very narrow and very long-pointed, shorter than the culm; head about 1´ long, dense or sometimes interrupted, ovoid or oblong; spikes few to many, those at the apex of the head usually staminate, the intermediate ones staminate at the summit, the lowest entirely pistillate and subtended by a bract about 1´ long; perigynium very strongly nerved on both faces, wing-margined above, sharply long-toothed, about the length of the scale.—Sea-beaches near Norfolk, Va. (McMinn). (Adv. from Eu.)
[*] 11.—[+] 5. Muhlenbergiànæ.