570 CYPERACE^E. (SEDGE FAMILY.; 



jecting beak or style about V long. (This long beak gives the name, from 

 nepas, a horn, and a"xpivoi, a rush.) 



13. R. eorniculata, Gray. (Hokned Rush.) Cymes decompound, dif- 

 fuse; bristles awl-shaped, stout, unequal, shorter than the achenium. — Wet places, 

 Penn. to Illinois, and southward. — Culm 3° -6° high. Leaves about 6" wide. 



14. R. macrostachya, Torr. Cymes decompound, or in the northern 

 form somewhut simple and smaller, and the spikes usually more clustered ; bristles 

 capillary, twice the length of the achenium. — Borders of ponds, Massachusetts, 

 Rhode Island, New Jersey, and southward: rare. — Perhaps it runs into the 

 preceding. 



13. CLADITJM, P. Browne. Twig-Rush. (Plate 5.) 

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

 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, decid- 

 uous. Achenium ovoid or globular, somewhat corky at the summit, or pointed, 

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

 kXoSo?, a twig or branch, perhaps on account of the twice branching styles of 

 some species.) 



1. C. mariseoides, Torr. Perennial; culm obscurely triangular 

 (l°-2° high); leaves narrow, channelled, scarcely rough-margined; cymes 

 small; the spikes clustered in heads 3-8 together on 2 to 4 peduncles; style 

 once 3-cleft. — Bogs, New England to Delaware, Illinois, and northward. July. 



14. SCLEEIA, L. Nut-Rush. (PI. 5.) 



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

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

 ones empty. Stamens 1-3. Style 3-cleft. Achenium globular, stony, bony, 

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

 leafy culms, mostly from creeping rootstocks : flowering in summer: all in low 

 ground or swamps. (Name o~Khnpia, hardness, from the indurated fruit.) 



1. S. triglomerata, Michx. Culm (2° -3° high) and broadly linear 

 leaves roughish ; fascicles of spikes few, terminal and axillary, in triple clusters, 

 the lowermost peduncled ; stamens 3 ; achenium smooth and polished, on an obscure 

 crustaceous ring or disk. — Vermont to Wisconsin, and common southward. 



2 S. reticularis, Michx. Culms slender (1° high); leaves narrowly 

 linear; clusters loose, axillary and terminal, sessile or the lower on short slen- 

 der peduncles ; stamens 2 ; achenium globular, regularly pitted-reticulated, not hairy, 

 resting on a double disk, each of three greenish appressed superposed calyx-like 

 lobes, the inner larger. — Eastern Massachusetts to Virginia and southward: 

 rare northward. 



3. S. laxa, Torr. Culms slender and weak (l°-2° high) ; leaves linear; 

 clusters loose, the lower mostly long-peduncled and drooping ; achenium globular, 

 irregularly pitted-reticulated or pitted-rugose, towards the base minutely hairy on the 

 somewhat spiral wrinkles : otherwise as in the foregoing. — E. Massachusetts to 

 New Jersey, Pennsylvania, and southward. 



