268 North American Cyperacea. 



C. filiculmis, Vahl, enum. 2. p. 328; Pursli, fi. 1. p. 51; Rcem. &f 

 Schult. syst. 2. p. 186 ; Sprcng. syst. 1. p. 218. 



C. mariscoides, Elliott, sk. 1. p. 67 ; Spreng. ! neue entdeck. 1. p. 239 ; 

 Torr.lfl. 1. p. 63, (excl. syn. ;) Bigel.fl. Bost. ed. 2. p. 19 ; Beck! hot. 

 p. 422; Chay! Gram. 8f Cyp. part 1. no. 74; Darlingt.! Jl. Cest. ed. 

 2. p. 16 ; Schult. mant. 2. p. 100. 



C. Killingaeoides, Pursh,Jl. 1. p. 50. (excl. syn.) 



Scirpus cyperiformis, Muhl.! gram. p. 41. 



S. lupulinus, Spreng. mant. 2. p. 30 ; Ra?n. Sf Schult. syst. 2. p. 135. 



Mariscus cyperiformis, Torr.! cat. j^l- N. York, p, 14. (excl. syn. 

 Pursh.) 



M. glomeratus, Bart, prodr. fi. Phil. 1. p. 30. (excl. syn. Vahl, Linn. 

 8f Pursh.) 



Rhizoma creeping. Culms cespitose, about a foot high, forming a 

 cluster of small tubers at the root, the sides striated and rather convex. 

 Leaves 1 — 2 lines broad, carinate, shorter than the culm, of a dull green 

 colour. Umbel often wanting, the spikelets being collected in a single 

 dense, globose head ; but usually there are one or two widely spreading 

 rays, each bearing a head of spikelets an inch in diameter. Involucre 

 3 — 4-leaved, twice as long as the umbel. Spikelets 5 — 6 lines long, 

 acute ; the florets somewhat distinct. Scales subcoriaceous, with a broad 

 scarious margin, strongly nerved, of an obscure yellowish-green colour ; 

 the upper ones more acute. StamensS. Style deeply 3-cleft. Nut two- 

 thirds the length of the scale, unequally triangular, minutely dotted in 

 lines. 



Hab. On dry hills, and in sterile fields, Massachusetts ! 

 to Florida ! and west to Arkansas ! — September. 



Obs. This species, to which I have restored the original 

 name of Vahl, appears to have greatly perplexed botanists. 

 Although it is a genuine Cyperus, it has been referred by some 

 to Mariscus, and by others to Scirpus. It is a very common 

 plant in all parts of the United States, and is easily distinguished 

 by its pale green colour, wiry stems, globose heads of spikelets, 

 and loose, broad, obtuse scales. 



21. Cyperus Grayii. 



Culm filiform, obtusely triangular, erect, tuberous at the base ; 

 leaves setaceous; umbel 4 — 6-rayed, somewhat erect; ochreae 



