CYPERACEAE (SEDGE FAMILY) 



179 



C. tiavus. 



(1.5-6 dm. high), much exceeding the smooth (or scabrous- 

 margined) flat (2-5 mm. wide) leaves ; umbel with numer- 

 ous ascending rays, the longest half as long as the involucre ; 

 heads globose, 1-1.5 cm. in diameter; spikelets 20-40, 

 greenish, rather loosely spreading, lance-cylindric, slightly 

 compressed, of 5-8 membranous veiny ovate-lanceolate scales 

 (the 2 lowest and the subulate 

 terminal one empty) ; achene ob- 

 long, 1.5-2 mm. long. Rich 

 sandy soil, Va. and Mo., southw. FIG. 230. 



31. C. riAvus (Vahl) Boeckl. Culms sharply 

 angled, smooth and wiry (2-5 dm. high), much exceed- 

 ing the smooth flat leaves; heads 3-6, cylindric (1-1.7 

 cm. long), sessile in a glomerule; involucral bracts 

 divergent or reflexed ; spikelets crowded, 2.5-5 mm. 

 long, dull, pale brown ; scales thin and veiny, the lowest 

 often persistent. Waste ground, about Philadelphia. 

 (Adv. from the Tropics.) FIG. 231. 



32. C. Grayii Torr. Culm thread-form, wiry (0.5-3 232. C. Grayii. 

 din. high) ; leaves almost bristle-shaped, channeled ; 



umbel simple, 4-10-rayed ; spikelets in a loose head, spread- 

 ing ; joints of the axis winged; scales rather obtuse, green- 

 ish-chestnut-color, barely exceeding the oblong or narrowly 

 obovoid achene. Barren sands, 

 Mass, to N. J., near the coast. 

 FIG. 232. 



33. C.Hought6niiTorr. Culms 

 obtusely angled (2-7 dm. high), 

 much exceeding the smooth nar- 

 row leaves ; umbel subsessile or 

 with a few elongate upright rays, 

 mostly shorter than the invo- 

 233. C. floughtonii. lucre ; spikelets linear-oblong, in 

 loose heads, spreading-ascendmg ; 

 scales roundish, strongly nerved, mucronate, yellow- 

 brown, barely exceeding the broad-obovoid achene. 

 Sandy soil, w. N. E. to Man. and Ore., locally s. to 

 Va., Kan., and Ariz. FIG. 233. 



34. C. filiculmis Vahl. Culm slender, wiry, often 



reclined (1.5-6 dm. high) ; leaves linear or filiform ; spikelets 

 numerous and clustered in one sessile dense head, or in 1-7 

 additional looser heads on spreading rays of an irregular 

 umbel, those of the principal glonierules 8-12-flowered (1-1.6 

 cm. long) ; joints of the axis naked or winged ; scales blunt, 

 or the upper mucronate, thin, yellowish-green ; achene 2 mm, 

 long. ( C. Bushii Britton. ) Dry sterile soil, Mass, to la., 

 and southw. ; rare northw. FIG. 234. 



Var. macilSntus Fernald. Usually low ; spikelets 4-8- 

 flowered (3-8 mm. long) ; scales firm, greenish ; achenea 

 235. cfii.,v.iuacil. shorter. Me. to Ont., s. to Va., O., and 111. FIG. 235. 



2. KYLLiNGA Rottb. 



Spikelets of 3 or 4 two-ranked scales, 1-1 ^-flowered ; the 

 2 lower scales minute and empty ; style 2-cleft and achene 

 lenticular ; spikes densely aggregated in solitary or triple sessile 

 heads. Culms leafy at base; involucre 3-leaved. (Named 

 after Peder Kylling, a Danish botanist of the 17th century.) 



1. K. pumila Michx. Annual; culms 0.6-3 dm. high ; head 

 globular or 3-lobed, whitish-green, 4-8 mm. broad ; spikelets 



234. C. filiculmis. 



