293 North American Cyperacece. 
times bear short leaves. Sjpike 12 — 16 lines in length. Scales coria- 
ceous, with a narrow scarious margin, sometimes a little pointed, often 
minutely dotted with purple. Bristles retrorsely hispid, four of them 
equalling the tubercle. Stamens 3. Style cleft about one-third of its 
length. Nut rather broadly obovate, somewhat tumid, grayish white, 
not shining ; the surface appearing very finely reticulate under a lens. 
Tubercle minute, dark brown, articulated to the nut by a very short 
neck. 
Hab. Swamps and margins of rivers, growing in the water. 
Near Philadelphia, Mr. StcirJumr and Mr. Z. CoUins ! ; 
Pomonkey Creek, Maryland, Dr. Rohhins; near Wilmington, 
North Carolina, alfr. Curtis! ; Carolina, Michaux! ; near New 
Orleans, Dr. In gal is ! 
Obs. This plant, as Michaux correctly remarks, resembles 
Scirpus mutatus, Linn. It has also a strong resemblance to 
S. acutangulus, Roxh. (Limnochloa, A^. ab E.) 3Ir. Elliott 
states, that in the rice fields of the South, it is a very injurious 
intruder ; its thick roots occupying the ground, and permitting 
nothing to grow where they extend. 
■§. 2. Spike cylindrical ; scales rigid, arranged in a spiral order; 
style S-cleft ; mit biconvex, tumid; pericarp very thicJc and 
spongy ; tubercle conical, spongy, confluent. — Somphocarya. 
3. Eleocharis cellulosa. 
Culm subterete above, obtusely triangular below, with a long 
truncate sheath ; spike cylindrical ; bristles longer than the 
nut, nearly smooth ; nut broadly obovate, cellular and reticu- 
lated, crowned with a broad conical subacute tubercle. 
Culms 2 feet high, 1^ line in diameter, spongy, invested one third of its 
length with a single sheath, obscurely 3-sided towards the base, but terete 
near the spike, scarcely striate. Spike an inch long, obtuse. Scales 
nearly orbicular, obscurely spiral, pale brown, sometimes dotted with 
red ; margin distinct, scarious, whitish. Bristles 6, strong, smooth, with 
