250 North American Cyperacece. 



1 — 8, 1830) has, in our opinion, clearly shown that the charac- 

 ters usually assigned to Papyrus, are insufficient for removing 

 that genus from Cyperus. This excellent botanist, however, 

 considers the " interior scales" of N. ab Esenbeck, as append- 

 ages of the glume immediately above them on the opposite side 

 of the rachis, from which they proceed obliquely downward, and 

 are inserted on each side of the rachis at the base of the sub- 

 jacent glume, the stamens and ovary of which they closely 

 embrace. In most of our species of Cyperus these scales or 

 appendages can be more or less distinctly seen, and it must be 

 allowed that they appear to constitute a part of the glume above 

 them ; but it may be doubted whether they are not mere winged 

 margins of the rachis, (from which they sometimes split off, as in 

 C. erythrorhizos,) rather than inner scales or bractese cohering 

 with the rachis. 



<^ 1. Style 2-cleft ; nul compressed-lenticular, Pycreus, 



1. Cyperus flavescens, Linn^ 



Umbel of 2 — 4 short rays ; spikelets Hnear, 14 — 20-flowered, 

 rather obtuse, fasciculate and solitary on the common rachis ; 

 flowers triandrous ; scales obtuse, one-nerved ; nut minutely 

 wrinkled transversely, suborbicular, slightly mucronate, shin- 

 ing. 



C. flavescens, Lhm. sp. 1. p. 68; Muhl. ! gram. p. 16; Elliott, sk, 

 1. p. 67? ; Torr.! fl. 1. p. 60; Big. ! fl. Boat ed. 2. p. 18; Beck! 

 hot. p. 421 ; Willd. sp. 1. p. 279 ; Ram. SfSchult. syst. 2. p. 191 v Spreng. 

 syst. 1. p. 223. 



Perennial. Culm 4 — 10 inches high, triquetrous, leafy near the base. 

 Leaves about a line and a half broad, as tall as the culm. Involucral 

 leaves 3, spreading thrice as long as the umbel. Rays of the vmbel 

 often very short, so that the spikes appear fasciculate; the longer ones 

 seldom more than an inch in length, each bearing from 4 to 10 spike« 

 lets, which are crowded mostly in fascicles of 3 — 4 on the common rachis. 

 Spikes half an inch or more in length, slightly tapering towards the sum- 

 mit, which is rather obtuse than acute, of a yellowish colour, sometimes 

 30-flowered. Scales broadly ovate, thin and m^embranaceous except on 



