322 North American Cyperacca, 
the base clothed with several sheaths which occasionally hear short 
leaves. Umbel (or rather cyme) growing from one to three inches below 
the summit of the culm ; or the inflorescence may be regarded as termi- 
nal, with a single-leaved straight involucre or bract at its base. Spikes 
nearly one third of an inch long, mostly ovate, but sometimes oblong, 
aggregated in threes at the summit of the peduncles or divisions of the 
umbel. Scales broadly ovate or obovate, obtuse, and frequently emar- 
ginate, mucronate, distinctly ciliate and clothed with a minute pubes- 
cence, generally marked with two or more curved wrinkles ; the sides 
ferruginous and dotted when young ; the keel green. Bristles 4 — 6, very 
thick, a little longer than the nut, retrorsely hispid. Stamens 3. Nut 
broadly obovate, dark brown, very minutely papillose, strongly convex 
in front, flat on the back. 
Hab. Lakes, fresh water ponds and swamps, from latitude 
60* north to the Gulf of Mexico, and from the Atlantic to the 
Pacific Ocean. 
7. SciRPUs TRiQUETER, Linn. 
Culm triquetrous, nearly leafless, (the base bearing one or 
two short leaves) ; spikes 1 — 5, aggregated, sessile, ovate- 
oblong; scales orbicular-ovate, mucronate; bristles slender, 
shorter than the nut; style 2-cleft; nut unequally doubly con- 
vex, acuminated. 
S. triqueter, Linn. ; Willd. sp. 1. p. 302 ; R. Brown, prodr. 1. p. 223; 
Ram. SfSchult. syst. 2. p. 141; Smith, Eng.fl. 1. p. 60; Kunth, syn. 1. 
p. 156 ; Michx. .' fl. 1. p. 47 ; Muhl. ! gram. p. 33. 
S. Americanus, Pers. syn. 1. p. 68; Pursh, fl. 1. p. 56; Elliott, sTc. 1. 
p. 80; Big. fl. Bost. ed. 2. p. 21 ; Torr. 1 fl. 1. p. 47 ; Beck, lot. p. 425 ; 
Gray •' Gram. 8f Cyp. 2. p. 135 ; Ram. Sf Schult. sysi. 2. p. 129. 
S. pungens, Vahl, enum. 2. p. 255 ; Ram. Sf Schult. syst. 2. p. 128. 
S. mucronatus, Pursh.' fl. 1. p. 55; Elliott, sk. 1. p. 80. 
Culm 3 — 5 feet high, slender, mucronate at the extremity, very acutely 
triangular, two of the sides concave, the other side flat ; sheaths at the 
base often bearing one or more leaves several inches in length. Spikes 
in a dense cluster near the summit, or some distance down the culm. 
Scales often emarginate, with the midrib produced into a point nearly a 
lint in length ; the sides ferruginous ; margin scarious and somewhat 
