246 CYPERACEAE. 



30. Cyperus Houghtoni Torr. Houghton's Cyperus. (Fig. 572.) 



Cyperus Houghtoni Torr. Ann. Lye. N. Y. 3: 277. 



1836. 



Perennial by tuber-like conns, culms very 

 slender, smooth, erect, i-2 tall. Leaves shorter 

 than the culm, i" wide or less, smooth, those of 

 involucre 3-5, the longer much exceeding the um- 

 bel; umbel simple, i-5-rayed, the rays mostly 

 short, their sheaths 2-toothed; spikelets loosely 

 capitate, linear, compressed, acute, 4 // -8 // long, 

 about \' f wide, n-15-flowered, falling away from 

 the axis when mature; scales chestnut brown, firm, 

 somewhat spreading, shining, oblong, obtuse, 

 truncate or apiculate, strongly about n-nerved^ 

 rachis very narrowly winged; stamens 3; style 

 3-cleft; achene broadly oblong, less then twice as 

 long as thick, 3-angled, brown, apiculate, nearly 

 as long as the scale. 



In sandy soil, Massachusetts to Minnesota, Kansas- 

 and Oregon. July-Aug. 



31. Cyperus Grayi Torr. Gray's 

 Cyperus. (Fig. 573.) 



Cyperus Grayi Torr. Ann. Lye. N. Y. 3: 268. 1836. 



Perennial by thick hard oblong or ovoid corms, 

 culms tufted, ascending or reclined, stiff, smooth, 

 very slender, 6 / -2o / long. Leaves shorter than 

 the culm, bright green, \" wide or less, those of 

 the involucre 4-8, the longer somewhat exceeding 

 the umbel; umbel 4-io-rayed, simple, the longer 

 rays $'-4? long; sheaths of the rays truncate or 

 nearly so; spikelets 2^ // -5 // long, loosely capitate, 

 compressed, linear, rigid, spreading; scales green, 

 ovate, obtuse or subacute, strongly i3-i5-nerved, 

 rather widely spreading when old; joints of the 

 rachis broadly winged; stamens 3; style 3-cleft; 

 achene oblong or oblong-obovoid, obtuse, apicu- 

 late, about two-thirds as long as the scale. 



In sands of the sea shore and in pine barrens, Massa- 

 chusetts to Florida. July-Sept. 



32. Cyperus echinatus (Ell.) Wood. Baldwin's Cyperus. (Fig. 574.) 



Mariscus echinatus Ell. Bot. S. C. & Ga. i: 75. />/. 3, 



f. i. 1816. 



Cyperus Baldwinii Torr. Ann. Lye. N. Y. 3: 270. 1836. 

 Cyperus echinatus Wood, Class-book, 734. 1863. 



Perennial by tuber-like corms, culm slender,, 

 smooth, erect, mostly longer than the leaves. 

 Leaves pale green, ij^ // -2 // wide, those of the in- 

 volucre 5-10, the longer usually much exceeding 

 the umbel; umbel simple, 6-i3-rayed; the rays fili- 

 form, their sheaths short, mucronate; spikelets 2"- 

 3" long, linear, flat, densely or loosely capitate in 

 globose heads; scales thin, pale green, appressed, 

 ovate-lanceolate, acute, 9-i3-nerved, with narrow 

 scarious margins; joints of the rachis broadly 

 winged; stamens 3; style 3-cleft; achene oblong- 

 obovoid, obtuse, one-half as long as the scale, about 

 twice as long as thick. 



In dry soil, sometimes a weed in cultivated fields. 

 North Carolina to Florida, west to Missouri and Texas. 

 July-Aug. 



