I^orth American Cyperacece. 369 



remarkable, as also its somewhat peculiar habit. Each spike- 

 let, as in the preceding species, produces a single perfect flower 

 at the summit, and all the scales are empty except the upper- 

 most. Were it not for its distinctly bifid style, this plant might 

 perhaps be properly referred to Cephaloschceims of Nees ab 

 Esenbeck. 



18. CERATOSCHGENUS, N. ah E. 



Spikelets producing a single perfect, and 1 — 4 stami- 

 nate flowers. Scales loosely and somewhat bifariously im- 

 bricated, the lower ones empty, the uppermost staminate or 

 abortive, Perigynium composed of 5 or 6 compressed, rigid 

 or cartilaginous, antrorsely hispid or scabrous bristles, which 

 are dilated and somewhat connate at the base. Stamens 3. 

 Style simple, or minutely bidenlate. Nut coriaceous, com- 

 pressed, smooth, crowned with the very long, distinct, indurated 

 and persistent, upwardJy scabrous style. — Culms triangular, 

 leafy ; corymbs mostly compound or decompound ; spikelets 

 large, clustered. 



1. C. longirostris. 



Schoenus longirostris, Miclix.l fl. 1. p. 87; Mulil. ! gram. p. 7. 



S. corniculatus, Lam'k. ill. gen. 1. p. 137.- 



Rhynchospora laxa. Vahl, enum. 2. p. 231 ; Torr. ! fl. 1. p. 58. 



R. longirostris, Ell. sk. 1. p. 59. 



R. corniculata, Gray ! monogr. I. c. p. 205. 



2. C. MACROSTACHYS. 

 Rhynchospora niacrostachya, Torr. ! in Gray, monogr. I. c. p. 206. 



Obs. These two plants, in accordance with the views now 

 generally adopted in the construction of genera in Cyperaceae, 

 cannot be allowed to remain in the genus Rhynchospora, from 

 which they also differ remarkably in habit. It was suggested 

 in the Monograph of N. American Rhynchosporae, that they 



