506 CYPERACE^E. (SEDGE FAMILY.) 



10. R. CCplialantlia, Torr. Leaves narrowly linear, fiat, keeled ; spifa* 

 very numerous, crowded in 2-3 or more dense globular heads which are distant (and 

 often in pairs), oblong-lanceolate, dark brown ; achenium orbicular-obovate, mar- 

 gined, narrowed at the base, about as long as the awl-shaped beak, half the 

 length of the stout bristles, which are barbed either downwards or upwards. Sandy 

 swamps, Long Island to New Jersey, and southward. Culm stout, 2 - 3 high : 

 the fruit, &c. larger than in the last, of which very probably it is only a marked 

 variety. 



14. CL.ADIUM, P. Browne. Twio-Rusn. 



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

 empty, one or two above bearing a staminato 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 proper tubercle. Perennials, with the aspect of Rhynchospora. 

 (Name from *Xa<W, a twig or branch, perhaps on account of the branching styles 

 of some species.) 



1. C. nmriSCOides, Torr. Culm obscurely triangular (l-2 high); 

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

 clustered in heads 3- 8 together on 2-4 peduncles; style 3-cleft. (Schcenus, 

 Muhl.} Bogs, New England to Penn., Ohio, and northward. July. 



15. SCL.ERIA, L. NUT-RUSH. 



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

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

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

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

 leafy culms. (Name (TK\r)pia % hardness, from the bony or crustaceous fruit.) 

 *< Achenium smooth and polished : its base surrounded by an obscurely triangular crus- 

 taceous ring or disk : stamens 3. 



1. S. triglonitir&ta, Michx. Culm (2 -3 high) and broadly linear 

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

 the lower peduncled; achenium ovoid-globnlar, slightly pointed (2" broad).- 

 Low grounds, Vermont to Wisconsin, &c. ; common southward. July. 



* =* Achenium reticulated, seated on a flatfish disk of 3 conspicuous and ovate-lan- 

 ceolate entire scale-like lol^es : stamens 2. 



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

 linear ; clusters loose, axillary and terminal, sessile or short-peduncled ; ache- 

 nium globular, deeply pitted betiveen the regular reticulations, not hairy. Sandy 

 swamps, Eastern Massachusetts to New Jersey, Virginia, and southward : rare. 

 August. 



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

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

 pitted and somewhat spirally marked with minutely hairy wrinkles. Sandy swamps, 

 Long Island, New Jersey, and southward, near the coast. Too like the last. 



