7 o 



FIELD COLUMBIAN MUSEUM BOTANY, VOL. III. 



Achene black, pyriform, .gx 1.7 mm., in section triangular, the facets 

 all equally concave and marked by horizontal reticulations resembling 

 a net, the meshes each including a single slight papilla. 



Hab. Izamal, Gaumer 2329, 2485, 2492, common at San Felipe, 

 14.03 ; east shore of island of Cozumel, Feb. 21, 1899, Millspaugh PL 

 Utowana 1596, Progreso, March 5, 1899, 1686. 



Cyperus compressus L. Sp. PI. Ed. 2:68. 



Bracts 4-5, leaf-like, 2-16 cm. long. Inflorescence a 2-5-rayed 

 umbel, i spike sessile, rays 1-5 cm. long. Spikes green, more or 



less mottled with chestnut at 

 maturity, flabellate, 12-25 cm - 

 wide, composed of 3-10 spikelets, 

 spreading or ascending from the 

 short rachis. Spikelets com- 

 pressed, oblong, 2x8-20 mm., 

 6-30 - fruited ; rachilla flattened, 

 wingless. Glumes more than 

 twice the length of the achene, 

 green, with pale or chestnut mar- 

 gins, closely imbricated, navicu- 

 late, broadly ovate, acuminate, 

 mucronate, keel thickened, lateral nerves obscure. Stamens 3. Style 

 longer than the achene, divisions short. Achene shining dark chestnut 

 or nearly black, turbinate, .9-1 x 1.3 mm.; in section triangular, the 

 angles with prominently rounded margins, the facets slightly concave, 

 marked by faint, regular, hexagonal ridges, the interspaces plane and 

 including a single slight papilla. 



Hab. Chichankanab, Gaumer 1291. 



Cyperus esculentus L. Sp. PL Ed. 2, 67. 



Bracts 2-5, leaf-like, 4-20 cm. long. Inflorescence a 4-io-rayed 

 umbel, rays .5-6 cm. long. Spikes golden brown, flabellate-oblong, 

 2-3 -cm. wide, of 5-25 

 spreading spikelets; rachis 

 .5-2.5 cm. long; bractlets, 

 when present, setaceous. 

 Spikelets compressed, ob- 

 long, 2-2.5x10-15 mm., 

 8-i4-fruited; rachilla hya- 

 line winged. Glumes 

 twice the length of the 

 achene, ovate, obtuse, 

 hyaline margined at sum- 

 mit, strongly 9-1 i-nerved, 

 golden brown, faintly 

 streaked with chestnut. 

 Stamens 3. Style more 

 than twice the length of 

 the achene, divided y$ its length. Achene shining light golden 

 brown, obovoid-oblong, .7x1.7 mm.; in section reniform-triangular, 



