North American Cyperacea. 267 
of the umbel slender, 1 — 2 inches long, somewhat erect. Involucre 
2 — 3 times as long as the umbel. Ochre(S with a short mucronate tip. 
Spikelets 16 — 24 on each ray, scattered along its upper half. Scales 
membranaceous, nerved, not mucronate. Stamens 3. Style 3-cleft 
nearly to the base. Nut light brown, obtusely angular in front. 
Hab. Near New Orleans, Hooker! 
Obs. For specimens of this distinct species of Cyperus, I 
am indebted to my most liberal friend Dr. Hooker, who received 
them either from Mr. Drummond, or Mr. Teinturier. In its 
slender and wiry cespitose culms, which are swollen at the base, 
this species resembles C. mariscoides Sf C. Grayii, but in its 
alternate spikelets it is more nearly related to C. rei)ens of 
Elliott. 
Involucre mostly 3-leaved. Spikelets three-fourths of an inch long, 
linear, somewhat obtuse when mature, for the most part distichously 
arranged on the common rachis ; the lowest ones frequently geminate or 
fasciculate. Scales yellowish, nerved, at length distinct at the point. 
Interior scales lanceolate, adnate,^yaline. Stamens 3. Style sometimes 
unequally 3-cleft. Nut acute. 
1 1 Spikelets aggregated in a capitate or svhumbellate manner 
on the summit of the rays. 
20. Cyperus filiculmis, VahL 
Culm triangular, tuberous at the base, assurgent ; leaves 
linear ; umbel simple, of 1—2 divaricate rays, or wanting ; 
ochreae pointless; heads globose, dense, composed of 15 or 20 
spikelets; spikelets linear-lanceolate, rather convex, 6 — 10- 
flowered ; rachis naked ; scales loose, ovate, obtuse or emar- 
ginate, slightly mucronate, scarious on the margin ; nut obovate- 
triquetrous, with a short acuminate point. 
