586 CYPERACE.E. (SEDGE FAMILY.) 



brown ; achene orbicular-obovate, margined, narrowed at base, about as long 



as the awl-shaped beak ; bristles twice longer, stout, barbed downward and 



sometimes also upward. Saudy swamps, Long Island to N. J. and Fla. 



2. CERATOSCHCENUS. SpiMets lanceolate, acuminate, in fruit flattish, 



cymose-panicled, of only one perfect and 1-4 staminate flowers ; scales few ; 



bristles rigid, minutely scabrous upward ; style simple or barely 2-toothed, 



filiform and gradually thickened downward, in fruit persistent as an exserted, 



slender-awl-shaped, upwardly roughened beak, several times longer than the 



smooth flat obovate achene; coarse perennials ; spikelets in flower 4", in fruit 



including the projecting beak about 1' long. 



13. R. COrniculata, Gray. (HORNED RUSH.) Culm 3 - 6 high ; leaves 

 about 6" wide; cymes decompound, diffuse; bristles awl-shaped, stout, unequal, 

 shorter than the achene. Wet places, Peun. to Fla., west to S. Ind. and Mo. 



14. R. macrostachya, Torr. (PI. 4, fig. 1-4.) Cymes decompound, 

 or in the northern form somewhat simple and smaller, and the spikelets usually 

 more clustered ; bristles capillary, twice the length of the achene. Borders of 

 ponds, Mass, to N. J. and Fla. ; rare. 



14. CLADIUM, P.Browne. TwiG-Rusn. (PI. 5.) 



Spikelets ovoid or oblong, of several loosely imbricated scales ; the lower 

 empty, one or two above bearing a staminate or imperfect flower ; the terminal 

 flower perfect and fertile. Perianth none. Stamens 2. Style 2- 3-cleft, de- 

 ciduous. Acheue ovoid or globular, somewhat corky at the summit, or pointed, 

 without any tubercle, in which it differs from Rhynchospora. (Diminutive of 

 /cAaSos, a branch, from the repeatedly branched cyme of the original species.) 



1. C. mariscoides, Torr. Perennial ; culm obscurely triangular (1-2 

 high) ; leaves narrow, channelled, scarcely rough-margined ; cymes small; the 

 spikelets clustered in heads 3-8 together on 2-4 peduncles; style 3-cleft. 

 Bogs, N. Scotia to Del., west to S. Minn, and Iowa. July. 



15. SCLERIA, Berg. Nux-Rusn. (PI. 5.) 



Flowers monoecious ; the fertile spikelets 1-flowered, usually intermixed with 

 clusters of few-flowered staminate spikelets. Scales loosely imbricated, the 

 lower empty. Stamens 1-3. Style 3-cleft. Achene globular, stony, bony, 

 or enamel-like in texture. Bristles, etc., none. Perennials, with triangular 

 leafy culms, mostly from creeping rootstocks ; flowering in summer ; all in 

 low ground or swamps. Inflorescence, in our species, of terminal and axillary 

 clusters, the lower clusters usually peduncled. (Name, aKXypia, hardness, from 



the indurated fruit.) 



* Achene smooth. 



1. S. triglomerata, Michx. Culm (H-3 high) and broadly linear 

 leaves roughish ; fascicles of spikelets few, the lowest peduncled, the upper 

 somewhat in threes ; achene ovate-globose or depressed, on an obscure crusta- 

 ceous disk. Mass, and Vt. to Fla., west to Minn, and Tex. Var. GRACILIS, 

 Britton. Culms slender (1-2 long); fascicles few-flowered, the lower (2- 

 3-flowered) on very long filiform peduncles; achene not more than half as 

 large, acutish. N. J. 



