North American Cyperacea. 255 



6. CyPERUS MICRODONTUS. 



Umbel with short crowded rays, or sessile ; spikes numerous, 

 lanceolate-hnear, about 14-flowered; scales deciduous, ovate, 

 rather acute, submembranaceous ; stamens 2 ; style deeply 2- 

 cleft ; nut oblong-obovate, obtuse ; rachis denticulate with the 

 inner scales. 



" C. brizseus ?" Schweinilz ! in litt. 



Annual. Culm cespitose, 2 — 4 inches high, triangular. Leaves a 

 line and a half broad. Umbel sessile, or with several rays scarcely half 

 an inch long. Involucre 4 — 5-leaved. Spikelets half an inch in length, 

 12 — 16-flowered, alternate on the common rachis. Scales spread- 

 ing but closely imbricated, indistinctly striate ; the keel narrow and 

 rather obtuse, green; the sides pale yellowish-brown; margin not sca- 

 rious. Interior scales persistent, giving the rachis a denticulate appear- 

 ance when the primary scales have fallen. Stamens always 2. Style 

 cleft more than half way down. Nut rather tumid, dark-gray, dull, 

 minutely dotted under a strong lens. 



Hab. Salem, North Carolina, Schweinitz! 



Obs. This species does not appear to have been hitherto 

 described. It cannot be the C. hrizcBus of Richard, which has 

 oblong-ovate spikelets. I have only received it from Mr. 

 Schweinitz. 



7. Cyperus Gatesii. 



Umbel of many (6 — 8) distinct rays ; spikelets somewhat 

 distant, alternate (with the lower ones fasciculately compound), 

 linear-lanceolate, 10 — 12-flowered ; scales oblong-lanceolate, 

 rather acute, loosely imbricate, submembranaceous ; stamens 

 2 ; style deeply 2-cleft ; nut oblong-obovate, obtuse ; rachis 

 with a narrow margin. 



Perennial. Culm nearly a foot high, slender, obtusely-triangular. 

 Leaves narrow, pale green ; those of the involucre about three in number. 

 Rays of the umbel very unequal, 4 or 5 of the longer ones about 2 inches 



Vol. m. 33 



