478 
long, spreading or drooping: perigynium thin and mostly shining, rather lightly 
about 10-nerved, ascending. (C. tentaculata Muhl.)—Swales, east of the Mississippi 
and to central Texas. Variable. 
+ + + Perigynium less inflated than in + +, more conspicuously nerved, and the teeth of 
the beak more or less setaceous: spikes nodding, comose or bristly in appearance. 
5. C. hystricina Muhl. Slender but erect (3 to 7 din.), with a sharp and rough 
culm and narrow leaves: pistillate spikes 1 to 3, approximate near the top of the 
culm, 2 to5 em, long, the lower one or two on filiform stalks, whitish or greenish- 
white in appearance, especially before pressed: perigyninm very strongly 15 to 20- 
nerved, the very slender beak strongly toothed, smaller than in No. 4: scale linear 
and rough, nearly or quite as long as the perigynium.—Swales, probably throughout 
western Texas. 
- + + + Mature perigynium tawny-yellow, obconic or obovoid, densely packed in short 
spikes. 
++ Terminal spike normally staminate. 
6. C, Frankii Kunth. Stiff and very leafy butlow (3 to 6 dm.), with an obtusely 
angled and smooth culm: pistillate spikes 3 to 5, the lower one or two short-stalked 
but erect, the remainder sessile on the zigzag top of the culm, all short (2.5 to 3 em.) 
and evenly ¢ylindrical and sometimes staminate at the top: perigynium very 
abruptly contracted into a short but slender beak which is usually shorter than the 
bristly seale. (C. stenolepsis Torr., not Less.) —Meadows and low places, Pennsylvania 
to Texas. The terminal spike is occasionally androgynous. 
++ ++ Terminal spike densely pistillate above. 
7. C. squarrosa L. Somewhat slender (5 to 10 dm, high), in clumps, with flat and 
weak leaves and sharp culm: spike sometimes single, but usually there are two or 
three, the lower ones being near the terminal one and short-peduncled, sometimes 
even nodding, all oblong, conical-oblong, or oblong-cylindric and exceedingly densely 
packed with pergynia, nut-brown: perigynium larger than in the last, the beak 
rough: seale short and usually entirely hidden.—Grassy places and copses, New 
‘ngland to Arkansas and evidently r paching our limits, 
2 * Perigynium dull, mostly large, thick and hard in texture, straight-beaked, not inflated : 
pistillate spikes mostly large and compactly flowered, erect or nearly so: stigmas 3,— 
TRACILYCHLAN A, 
8. C. riparia W. Curtis. Very stout and large (6 to 15 dm. high), from creeping 
roots, with broad, thick and glaucous leaves: staminate spikes usually 2 or 3, aggre- 
gated on a common stalk: pistillate spikes 2 to 4, scattered and more or less 
peduncled, the lowest often very long-stalked, ordinarily 5 to 10 em. long, mostly 
loosely Howered below: perigynium ovate-lanceolate, rather lightly many-nerved 
and becoming shining, the beak short and thick: scale various, mostly shorter than 
the perigynium,—Swales, throughout most of the United States, reaching part way 
across Texas. 
3 * Distinguished from 2* by the much smaller and short perigynium, which is only 
slightly or not at all beaked and which is much thinner in texture, by very narrow 
slender spikes, and stigmas 2 (3 in No. 11).—MicroruyNncue, . 
+ Pistillate scales not awned, mostly not exceeding the periqynium. 
9. C. stricta Lam. Tall and slender, but erect (5 to 15 dm. high), forming dense 
tussocks when growing in boggy places, the culm sharp and leaves long and nar- 
row: pistillate spikes 3 to 5, variable in size, 2.5 to 7 em. long and narrowly cylin- 
drical, compactly flowered above but often alternate at the base, scattered, the 
