FEB. 1903. PLANTS YUCATAN^E MILLSPAUGH & CHASE. 



with a prominent border of deep irregularly hexagonal air cells overly- 

 ing the hard endocarp. This layer of air cells gives to the achene a 

 translucent, "bubbly" appearance. 



f Hab. Chichankanab, Gaunter 1511, 24.51. 



The species, though flowering abundantly, rarely perfects its 

 achenes. 



Cyperus rotundus L. Sp. PI. Ed. 2, 67. 



Bracts 3-5, leaf-like, i-n cm. long. Inflorescence a 3~7-rayed 

 umbel, i spike subsessile, rays 1-7 cm. long, sometimes compound. 



Spikes wine-color, flabellate-oblong, 

 2-3 cm. wide, of 2-7 spreading 

 spikelets, rachis 2-10 mm. long. 

 Spikelets compressed, oblong, 

 1.5-2x5-20 mm., 6-24-f ruited ; 

 rachilla hyaline winged. Glumes 

 twice the length of the achene, ovate, 

 obtuse, strongly 5-7 -nerved, wine- 

 color, with an olive-green keel. 

 Stamens 3. Style 3 times the length 

 of the achene, divided ^ its length. 

 Achene ashy brown (reddish when 



immature), oblong, .6-.7XI-4 mm.; in section depressed triangular, 

 the ventral facet broadest and slightly concave; the marking similar 

 to that of esculentus but air cells much shallower and interspaces 

 sunken. 



Hab. "Common in moist places near Merida, i foot high," 

 Gaumer 1087, 1088, Chichankanab, 2i?j. 



This species, like the preceding, rarely perfects fruit, both repro- 

 ducing by tubers. 



MARISCUS. Characters of Eucyperus except: rachilla slightly 

 winged, falling away from the axis, two lower empty glumes per- 

 sistent. 



Cyperus echinatus (Ell.) Wood Class Book 734. 



Mariscus echinatus Ell. 



Cyperus globulosus Aubl. ? 



Bracts 2-5, leaf-like, 

 2-10 cm. long. Inflores- 

 cence a i-8-rayed umbel, 

 i spike sessile (inflores- 

 cence sometimes reduced 

 to the single sessile spike), 

 rays .5-3 cm. long. Spikes 

 russet, subglobose, 8-12 

 mm. wide, of 10-25 con- 

 gested spikelets on a re- 

 duced rachis. Spikelets 

 little compressed, oblong 

 2x6 mm., 3-4-fruited; rachilla broadly hyaline winged. Glumes less 

 than twice the length of the achene, ovate, obtuse, minutely speckled 



