This section is from the book "Class-Book Of Botany USA&Canada", by Alphonso Wood. Also available from Amazon: Class-Book Of Botany.
43 C. cristata Schw. Spikelets 6 - 14, globous, sessile, closely aggregated into an oblong, thickhead of a crested form, bracteate; perig. ovate, oblong, compressed, winged, rostrate-acuminate, bifid, concavo-convex, scabrous on the margin, longer than the oblong, lanceolate glume; st. 1 - 3f, acutely triangular. - Plant yellowish-green. Common in fields and meadows on colder soils. (C. lagopodioides β. Carey.)
44 C. lagopodioides Schk. Spikelets 8 - 20, beakless, green, ovate, rather near, alternate and sessile; perig. round-lanceolate, tapering at both ends, concavo-convex, nerved, bidentate, scabrous on the margin, nearly twice as long as the ovate-lanceolate glume; st. nearly 2f, leafy; the whole light green. - Common (C. scoparia, β. Torr.)
45 C. tenera Dew. Spike compound, recurved; spikelets about 5, obovate, remotish, alternate, sessile, attenuated below, the lowest bracteate; fr. tawny, ovate, compressed, somewhat winged, rostrate, nerved, ciliate-serrate, longer than the oblong-lanceolate scale; st. 15 - 30', small and slender, erect, with a nodding spike, longer than the leaves. - Light green. Common. (C. straminea β. Torr. C. festucacea β. Carey. The inconsistency of these synonyms favors our own view of this species.)
46 C. festucacea Schk. Spike erect; spikelets 5 - 8, obovate and clubform, sessile and alternate, approximate, lower one bracteate; perig. tawny, roundish-ovate, rostrate, winged, striate, 2-toothed, scabrous on the margin, longer than the ovate, lanceolate glume; st. 15 - 30', erect and stiff, leafy below. - Plant pale green. Spikelets greenish to brown. Common in fields, but not abundant The club-form spikelets from the decurrent scales of the
flowers, especially mark this species.
47 C. adusta Boott. Spikelets several, 4 to 8 or more, often not approximate, tapering below in maturity; perig. ovate-lanceolate, or ovate, long-rostrate, narrow-winged and serrulate, veined, scarcely bifid, as long and broad as the glume; culm 15 to 24', leafy towards the base. - R. I. (Olney) to L. Sup. and Brit. Am.
48 C. scoparia Schk. Spikelets 5 - 10, usually 5 - 7, ovate, sessile, approximate, the lowest with a long, deciduous bract; perig. ovate-lanceolate, nerved, erect, slightly margined, glabrous, longer than the lanceolate, acuminate glume; st. 18 - 24', leafy towards the root. - Moist places, very common. (C. ovalis Ell.)
β. AGGREGATa Dew. Spikelets aggregated into a head, somewhat spiral.
49 C. sychnocephala Carey. Spikelets ovate, closely aggregated into a head (as the name purports), sessile, slender, with long, leafy bracts; perig. ovate, very long, lanceolate, or tapering into a long beak, with scabrous edges, a little longer than the lance-ovate glume; plant short and very pale green. - N. Y., Jefferson Co. (Boott. Ill, 111), at Little Falls (Vasey, Kneiskern). Remarkable for its slender, beaked fruit.
50 C. arida Schw. and Torr. Spikelets oval-oblong, 5 - 10, somewhat tapering at both ends, large and approximate, close-flowered, dry and chaff-like; perig. lance-linear, compressed, thin, distinctly winged, bidentate, nerved, acuminate, twice longer than the ovate-lanceolate glume; plant light green in all its parts. - Common in Ohio and Mich., 18 - 36', and further W. and S. (C. Muskingummensi3 Schw., scoparia, β. Torr.)
51 C. miliaris
Mx. (B. t. 187.) Culm erect, slender, lough above; lvs. flat, very narrow; . spike sessile, sometimes 2 and distant, ovoid, tawny; bract setaceous, short;
spike pale, rather long-pedunclcd; perig. spheroidal, smooth. - Marshes, Can., especially at L. Mistassins.
52 C. Floridana Schw.
Spike short and sessile;
spikes 2 to 4, approximate, ovale, sessile, bracteate, the lowest sometimes a little recurved; perig. ob-long, tapering below, rather obovate, plano-convex, abruptly rostrate, short-bifid, scabrous above and on the back, about as long as the ovate-oblong, red-edged, scabrous, cuspidate glume; culm 2 to 6', slender, 3-sided; lvs. radical, flat, twice to thrice longer than the culm; plant pale green; ach. oval, lens-shaped. - Fla, to La.
53 C dubitata Dew.
Spike erect, oblong, short, with oblong, obtuse, black, white-edged glumes;
spikes 2 to 4, ovate, sessile, approximate, the lowest oblong and short-pedunculate, subremote, leafy-bracted, all black; perig. oval, short-apiculate, concavo-convex, orifice entire, equaling or slightly exceeding the oblong-obovate, black, white-edged glume; culm, 8 to 12, triquetrous, smooth, still; with flat, smooth lvs. (C. saxatilis Ed. 1st.) - Probably this is the plant called C. saxatilis L. in the Flor. Dan., in Eng. Bot. and of Schk. But as Dr. Boott proves (U saxatilis (L) and C. pulla (Good.) to be the same, this plant can belong to neither, It is called C. rigida (Good.) by Carey in the Manuel of Gray, but differs from it in many characters given by Goodenough in his full description.
54 C. lenticularis Mx. (B. t. 76). Spikes cylindric, obtuse, rather slender, near, sessile except the lowest;
spike 1, rarely 2, 1' long, or the lower shorter;
spikes 2 to 5, mostly 4, leafy-bracted, not dense flowered, the lowest more remote and attenuated below; perig. ovate-elliptic, slightly convex both sides, pale, then yellowish, short-beaked, longer than the narrow-oblong, obtuse glume; culm 8 to 12' high, smooth, triquetrous, with flat leaves; bracts not sheathing, the lowest overtopping the stem. - At L. Avalanche, N. Y. (Torr. & Gray), to Bear L. (Richardson).
 
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