North American Cyperacea. 279 



}3ressed, slightly mucronate, nerved, somewhat scarious on the margin; 

 the two lowest much shorter than the others. Interior scales per- 

 sistent, and forming a winged margin to the rachis. Stamens 3. Style 

 3-parted. Nut flattened on the back, dull grayish brown. 



Hab. Boggy grounds, and also in dry soils ; cominon. 

 New York ! to Florida ! and west to Arkansas ! — August to 

 October. 



^. tenellus; culms cespitose, slender, heads ovate, small. 

 Gray, Gram. S^- Cyp. part 1. no. 77. (excl. sj^n.) Culms 4 inches to a 

 foot high. 



Hab. Sandy places in the pine barrens of New Jersey ; 

 common. 



y. cylindriats ; heads oblong, or cylindrical. 



Mariscus cylindricus, Elliott, sic. p. 74; Schult. mant. 2. p. 143. 



M. umbellatus, Pursh! fl. 1. p. 59. (excl. syn.) 



M. neglectus, Schult. mant. 2. p. 144 (founded on Scirpus, no. 31. 

 (without a name) Muhl. gram. p. 46.) 



Culms 2 feet or more in height. Umbel 5 — 7 rayed, the raj's some- 

 what erect. Heads or spikes varying from ovate to cylindrical, compact. 

 Sjdkclets 3 — 4-flowered. Scales and nut as in the preceding variety'. 



Hab. Sandy soils ; sometimes in wet situations. Common 

 in the Southern States, as far south as Louisiana. 



Obs. I have removed the Mariscus ovidaris of Vahl to this 

 genus, because I cannot discover it to possess characters suffi- 

 cient to distinguish it from many undoubted species of Cyperus. 

 Indeed all the species of Mariscus which have fallen under my 

 observation (with the exception, perhaps, of ilf. retrofractus) 

 resemble, in the structure of their flowers, the plant above 

 described. The 2 valves of the common calyx of Mariscus can 

 only be regarded as short abortive scales, such as occiu* in 

 Cyperus jlavescens, dentattcs, articulatus, and many others. Little 

 dependence can be placed on the number of florets in the spike- 

 let, as there are six and even eight in the M. dilutus of N. ab 

 Esenbeck. R. Brown {prodr. 1. p. 2 IS) describes the spikelet 

 as roundish (spicula teretiuscula), but this character exists in 



Vol. m. 36 



