56 



CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



keeled, loose, glabrous or toward the summit scabrous, or rarely ciliate; 

 ligule ciliate, about 0.8 mm. loug; blades 10 to 40 cm. long, or rarely longer, 

 6 to 12 mm. wide, rather thin and lax, flat or folded at the rounded base, 

 scabrous on the upper surface and usually pilose, glabrous on the lower surface 

 or scabrous toward the summit ; spikes finally rather long-exserted, 5 to 14 cm. 

 long, dense or loose at the base, the axis strongly angled, scabrous, a tuft of 

 white hairs usually borne just below the burs, the summit prolonged beyond the 

 uppermost bur into a slender point 2 to 3 mm. long ; burs globose, the body 

 about 5 mm. high, as broad or broader, densely villous, tawny, the numerous 

 slender bristles antrorsely scabrous, commonly purplish, the inner more than 

 twice as long as the body, the lobes of the body about 8, interlocking at ma- 

 turity ; spikelets usually 3, exceeding the body of the involucre, 4 to 4.5 mm. 



Fig. 10. — Cenchrus pilosus. From the type specimen of C. pallidus. 



long, about 1.8 mm. wide, acuminate ; first glume obsolete ; second glume and 

 sterile lemma shorter than the fruit, thin, very minutely puberulent ; fruit 

 turgid, the palea minutely puberulent between the nerves except toward the 

 base. 



DISTRIBUTION. 



Moist open ground up to about 1,000 meters altitude, southern Mexico to 

 northern South America. 



Morelos: Yautepec, Pringle 11219. 



Colima : Jala, Hitchcock 7050. 



Guerrero : Balsas, Amer. Or. Nat. Herb. 620. Iguala, Pringle 8394. 



Oaxaca : Tomellin, HitcMock 6217. Tehuantepec, Liebmann 465. 



Yucatan : Izamal, Millspaugh 70. Merida, Collins 22. 



Salvador : Acajutla, Hitchcock 8997. Sonsonate, Hitchcock 8978. 



Nicaragua : San Juan del Sur, Hitchcock 8596. Masaya, Hitchcock 8628, 8739. 



Jinotepe, Hitchcock 8667. Corinto, Hitchcock 8619. 

 Colombia : Santa Marta, Smith 153. 

 Venezuela : El Valle, Miller & Johnston 179. 

 Curacao : Willemstad, Britton d Shafer 3156. 



