FEB. 1903. PLANIVE YUCATAN,*: MILLSPAUGH & CHASE. 



79 



surfaces marked by prominent horizontal intermitting ridges com- 

 posed of oblong, raised cells, the interspaces shallow and narrow. 

 Hab. Mangrove swamp, Sisal, Nov. 9, 1865, Schott 176. 



Dichromena radicaus Cham, et Schl. Linnea 6:38. 



Bracts 3-5, minutely ciliate and sometimes white at the base. 



Heads 8 x 10 mm. , composed of 1-3 light 

 cinnamon-brown spikelets 9x3 mm., 

 lanceolate, 5-fruited; glumes with dark- 

 er cinnamon keel, triangular-ovate, ob- 

 tuse, 3 times the length of the achene. 

 Stamens 3. Achenes (excluding the 

 beak) dark brown, orbicular, .9x1 mm. 

 Beak black, sharply conical, sagittate, 

 .3 mm. high. Achene in section ellip- 

 tical, the angles slightly marked; the 

 surfaces marked by about 12 horizon- 

 tal, intermitting ridges composed of small, oblong, raised cells, with 

 deep broad interspaces. 



Hab. Boggy soil, center of the island of Cozumel, Feb. 20, 

 1899, Millspaugh PI. Utowana 1562. 



SCIRPUS L. Sp. PI. 47. 



Flowers perfect, glumes many, spirally imbricated. Perianth of 

 2-6 bristles. Stamens 3. Style (in our species) 2-cleft, wholly 

 deciduous. Achene biconvex. Spikelets solitary or variously clus- 

 tered at the summit of the culm. 



Scirpus validus Vahl Enum. 2:268. 



Scirpus lac us - 

 tris of American au- 

 thors not Linnaeus. 



Inflorescence a 

 compound, lax, 

 more or less droop- 

 ing umbel, subtend- 

 ed by a single erect, 

 attenuate, terete 

 bract, channeled at 

 the base, 1-4 cm. 

 long; rays 1-4 cm. 

 long, flattened, sca- 

 brous; bractlets 

 lanceolate, mucro- 

 nate, scarious, pu- 

 bescent toward the 

 summit, fimbriate- 

 ciliate; secondary 

 rays .5-4 cm. long, 

 like the primary. 

 Spikelets in capitate clusters of 1-5; oblong-ovoid, obtuse, 3 



-4 x 6-9 



