528 CYrr.itAcr.j:. (skdok i amii.v.) 



lute; nut ol>ov:ito fi'otn u slalk-liki" Ituse, Icntiriiliir ; tiilxTcle siilmlato, ns lonj^ ns 

 the rut, with its dihitcd base equiilliii"^ it in width ; hristh.>s C, stout, nearly as long 

 Bs the nut and tubercle. — Var. I'Axirui.ATA. (R. jianieuhita, C/«//.) Culms 

 stout (3°--4° liigli) ; leaves flat (2"-3" wide) ; corymbs compound, panieulatc, 

 with tlie very numerous spikes clustered at tiic summit of tiie brunches. — Hogs 

 and springy ])hues, Florida to North Carolina, and westward. July -Sept. 



27. R. cephalantha, Gray. Culms (2°-3° high) nearly terete ; leaves nar- 

 rowly linear ; curvnibs 4-8, mostly by pairs, gloliose, compact; sjiikes numer- 

 ous, lanceolate-ol)long, dark brown; nut broadly obovate from a stalk-like base, 

 compressed, almost truncate at the apex, and mueh wider than tiie base of the 

 subulate tul>ercle; bristles 6, as long as the nut and tubercle. — Bogs and shady 

 swamps, Florida, and northward. July and Aug. 



^ 3. HALOSCIICEXUS. PerUinth none. 



28. R. pusilla, n. sp. Culms (6'- 12'high) and leaves bristle-form ; cor}'mbs 

 2-3, distant, crect-spil'ading, the ujjjjer one compound; spikes minute, ovate, 

 mostly scattered on the brandies, 3-flowered; scales ovate, brown; nut wliite, 

 oblong-obovatc, compressed-lenticular, contracted at the base, transversely 

 wrinkled ; tubercle depressed-conical, free at the base. — Margins of pine-barren 

 ponds, Middle and AVest Florida. June. 



29. R. divergens, n sp. Culms (6'- 12' higli) and leaves filiform or bristle- 

 form; corymbs 2-3, distant, spreading; spikes small, scattered, pedicelled, 3- 

 flowered; scales brown, ovate ; nut obovate, biconvex, minutely pitted ; tubercle 

 depressed, sessile, minutely pointed in the centre. — Low pine barrens, Florida 

 to South Carolina. June. 



30. R, Chapmanii, M. A. Curtis. Culms (12'- 20' high) densely tufted, 

 erect, setaceous or filiform, like the short and flat leaves ; corymb solitary, terminal, 

 capitate; spikes whitish, lanceolate, densely elu.«tered, I -flowered ; scales 5, the 

 uppcnnost fertile ; nut oval, lenticular, smooth and shining; tubercle short, ses- 

 sile, broadly conical; stamens 1-2. — Flat pine baiTcns, Florida to South Caro- 

 lina. July and Aug. 



15. CERATOSCHCENUS, Necs. Horned Rush. 



Spikes few-flowered. Scales loosely imbricated, the lower ones empty, the 

 upper with staminate or abortive flowers. Perianth of 4-6 bristles, wliicli arc 

 dilated and connate at the base. Stamens 3. Style elongated, entire or slightly 

 2-cleft at the apex. Xut compressed, crowned with the persistent and hispid 

 lower half of the style. — Perennials. Culms jointed, leafy. Spikes scattered 

 in an open corymb, or clustered in a globose head. 



1. C. corniculatus, Nees. Culms stout (3°-4° high), 3-angled ; leaves 

 flat, scabrous on the edges (6"- 10" wide) ; corymbs 3 -5, erect, compound ; spikes 

 brown, ovate-lanceolate ; style very long, the lower and persistent portion up- 

 wardly scabrous ; nut narrowly obovate, smooth, the sides concave and minutely 

 dotted ; bristles 5-6, rigid, smoothish, half as long as the nut ; tubercle subulate, 

 3-4 times the length of the nut. (Rhynchospora longirostris, Ell) — Ponds 



