344 North American Cyperacect^ 



Species of Isolepis, Vahl. 

 Species of Scirpus, Linn., Willd. 



3. FlMBRISTYLIS BaLDWINIANA. 



Culm sulcate and somewhat compressed ; leaves mostly ra- 

 dical, channelled, serrulate, nearly as long as the culm ; umbel 

 few-spiked, simple or somewhat compound, shorter than the* 

 involucre; spikes ovate, acute; scales broadly ovate, somewhat 

 mucronaie ; nut marked with tuberculated ribs and transverse 

 strias ; style somewhat ciliate. 



Scirpus sulcatus, Elliott! sk. 1. p. 86, (not of A. cle P. Thoxiars);r 

 Spreng. syst. 1. p. 212. 



S. Baldwinianus, Sdmlt. mant. 2. p. 85; Darlingi. ! fi. Cest, ed. 2. p*- 

 18. 



S. ferrugineus, Darlingt. ! fl. Cest. ed. 2. p. 7. 



Culms cespitose, deeply sulcate, 2 — 12 inches high, smooth. Leaves 

 narrow, channelled on the upper surface, sometimes overtopping the- 

 culm, slightly ciliated with very minute teeth or serratures, sometimes 

 hairy. Involucre about 3-leaved ; one of the leaves longer than the 

 umbel, all of them denticulate like those of the culm. Umbel mostly 

 simple ; rays 2 — 4, seldom more than three-fourths of an inch long,, 

 sometimes divided. Spikes 3 lines long, acute or somewhat acuminated.^ 

 Scales membranaceous, with a short abrupt mucronate point; the sides 

 yellowish brown ; keel green; Stamen solitary. /SZ^/Ze dilated at the- 

 base into a roundish bulb, the whole at length separating from the nut ; 

 the divisions spreading and recurved. Nut obovate, whitish, marked on 

 each sides with 6 — 8 prominent ridges, sometimes with a number of 

 warts towards the simimit. 



Hae. Damp clayey soils, Pennsylvania to the Gulf of 

 Mexico, and west to the Mississippi. West Chester, Penn- 

 sylvania, Dr. Darlington! ; near Charleston, South Carolina,, 

 EUiott ! ; Riceborough, Georgia, L. Lc Conte, Esq.! ; St. 

 Louis and New Orleans, T. Dnimmo7icl! 



Obs. Allied to F. laxa, Vahl, and also to F. annua, H, 

 ^ S. My St. Louis and New Orleans specimens have the 



