3S4 North American Cyperacea. 
forming somewhat compound corymbs. Scales membranaceous, some- 
what pubescent, chestnut coloured ; the summit a little cleft each side of the 
Inidrib, which is produced into an awn-like cusp or bristle about 2 lines 
long and recurved so as to give the spikes a squarrose appearance. 
Bristles 3 — i, very slender, about two-thirds the length of the nut, re* 
trorsely scabrous. Nut large, nearly orbicular, much compressed, dark 
brown, and polished, tipped with the minute base of the style. 
Hab. Salt marshes, and ditches near salt water ; not found 
far from the sea shore ; Mahie to Florida. 
Obs. Mr. Arnott thinks that the Scirjpus affinis of Roth and 
N. ab Esenb. (1. c.) approaches so near S. maritimus, that the 
two species cannot always be distinguished, and in this opinion 
I agree. 
/3 ^ jluviatilis. C ulm triquetrous, leafy ; umbel somewhat 
compound, shorter than the involucre ; spikes ovate, (large and 
thick,) acute; scales ovate, lacerately 3-toothed ; the midrib 
produced into a bristle; nut obovate, triangular, narrowed 
downward, (dull,) acuminate, as long as the (6) rigid bristles. 
S. maritimus, Elliott, sic. 1. p. 86 ? ; Gray! Gram. Sf Cyp. part 1, 
no. 82, (in part). 
S. macrostachyos, Mulil. ! gram. p. 45, (in part.) 
Culm 2 — 4 feet high, acutely triangular, smooth, leafy below. Leaves 
as tall as the culm, more than half an inch broad, smooth on the margin 
and keel. Umbel composed of 10 — 20 spikes; the principal rays about 
5, 1 — 3 inches long, semiterete ; the subdivisions bearing at their extre- 
mity 2 — 3 or more spikes in a dense cluster. Involucre 3 — 5-leaved, 
much longer than the umbel. Spikes nearly an inch long and about 
half an inch in diameter, rather acute even in fruit. Scales thin and 
scarious, pubescent, rarely emarginate, of a pale brown colour, lacerately 
3-toothed each side of the midrib, which is produced into a flat recurved 
cusp or short bristle. Bristles mostly 6, straight and stiff, unequal ; the 
longest somewhat exceeding the point of the nut. Style unequally 3- 
cleft, rarely 4-cleft. Nut more than 2 lines long, triangular with the 
sides equal and nearly plane, gradually narrowed downward, abruptly 
acuminated, of a dull grayish colour, very minutely papillose. 
Hab. Swamps along the borders of rivers and lakes, 
always in fresh or only slightly brackish water. Common in 
