260 North American Cyperace^B. 
Annual. Cuhi 12—15 inches high, firm and erect, thickened and red- 
dish towards the root. Leaves commonly shorter than the culm, 3—4 lines 
wide. Involucre 5— 6-leaved, many times longer than the umbel. Rays 
of the umbel 4—6, the naked part scarcely more than an inch in length, 
mostly divided at the summit, and sometimes bearing short setaceous 
involucels. Spikelets much crowded on the rays, the lower ones com- 
pound, about three-fourths of an inch long, at first compressed, but nearly 
terete when mature. Scales of a rather firm texture, not scarious on the 
margin, loosely imbricated, somewhat indistinctly striate. Rachis very 
broad and thick, separating at the joints when mature. Interior scales 
adnate, persistent, appearing like obtuse auricles, folding round the nut 
and firmly embracing its base. Stamens 3. Style 3-cleft more than half- 
way down. Nut whitish, somewhat acute, flattened on the back, ob- 
tusely angled in front, puncticulate. 
Hab. Borders of salt marshes. Common in New Jersey, 
particularly in the neighbourhood of Hoboken ; Salina, New 
York, J. Carey! ; Carolina, Michaux!; Wilmington, North Ca- 
rolina, Mr. Curtis!; Georgia and Delaware, Dr. Baldwin; New 
Orleans, Dr. Ingalls ! 
Obs. This plant probably grows in many parts of the 
Atlantic States, being confounded either with C. styigosi/s or C. 
erythrorhizos. It is clearly the C. strigosm of Michaux, as I 
have ascertained by examining his herbarium ; and he correctly 
describes the plant as having suhterete spikelets. To the C. 
'pennatus of Lamarck (of which I possess a specimen from A. 
de Jussieu,) it is very nearly allied, not only in general appear- 
ance, but in the structure of the spikelets. That species, how- 
ever, has a loose corymb, longer spikelets, slightly mucronate 
glumes, and an oblong nut. 
13. Cyperus tetragonus, Elliott. 
Umbels many-rayed, without involucels ; spikes oblong, cy- 
lindrical ; spikelets 3 — 5-flowered, somewhat quadrangular ; 
scales slightly mucronate ; nut oblong. 
C. tetragonus, Elliott, sh. 1. p. 71 ; Schult. mant. 2. p. 130. 
