HITCHCOCK AND CHASE — NORTH AMERICAN GRASSES. 19 



Vibgin Islands : St. Thomas, Britton & Marble 1230. Tortola, Shafer 1147. 

 Trinidad : Port of Spain, Hitchcock 9962 ; Amer. Gr. Nat. Herb. 589. St. Joseph, 



Hitchcock 10020. Tabaquite, Hitchcock 10120. Caparo Woods, Broadway 



4923. Tainana Forest, Broadway 4952, 4959. Cedros, Hitchcock 10151. 

 Tobago: Hitchcock 10261, 10262, 10269, 10275; Broadway 3551, 4038. 

 Colombia : Miraflores, Pit tier 875. Cuesta de Tocota, Pittier 685. 

 British Guiana: Meyer. 

 Dutch Guiana : Hostmann 512. 

 French Guiana: lies du Salut, Sagot 656. 

 Brazil: Corcovado, Rose 20156, 20312. Bahia, Salzmann. Santa Rita, Putte- 



mans 3657. Parana, Dus6n 11487, 14050. Matto Grosso, Malme 3357. 



Rio Janeiro, Widgren. Without locality, Riedel. 



Explanation of Plate 14. — Lasiacis ligulata. Specimen from Tobago, Broadway 4038 

 (U. S. Nat. Herb. no. 725606). Natural size. 



6. Lasiacis rhizophora (Fourn.) Hitchc. 



Panicum rhizophorum Fourn. Mex. PI. 2: 31. 1886. Several specimens are 

 cited from Orizaba and one from Martinique. The first specimen is selected 

 as the type (Orizaba, Bourgeau 3025). 



Lasiacis rhizophora Hitchc. Proc. Biol. Soc. Washington 24 : 145. 1911. Based 

 on Panicum rhizophorum Fourn. 



DESCRIPTION. 



Plants branching and straggling, not forming a strong central cane, decum- 

 bent at base and rooting at the lower nodes, the fertile culms ascending, 

 30 to 100 cm. long, glabrous or pubescent; sheaths appressed-hispidulous or 

 glabrescent, villous on the margin ; ligule inconspicuous ; blades lanceolate to 

 ovate-lanceolate, 7 to 14 cm. long, 1.5 to 3 cm. wide, somewhat cordate at base, 

 rather abruptly narrowed above to an acuminate point, pubescent or scabrous 

 beneath, scabrous above; panicles 8 to 15 cm. long, the branches stiffly ascend- 

 ing, naked below, the spikelets clustered toward their tips, the axes scabrous ; 

 spikelets 3 to 4 mm. long, ovoid. 



DISTRIBUTION. 



Copses and edges of woods, southern Mexico to Costa Rica. 



Veracruz: Cordoba, Hitchcock 6461. Zacuapan, Purpus 6205. Orizaba, Bour- 

 geau 3025; Beaton 60. 



Guatemala: Chupadero, Heyde & Lux 3915. Coban, Tiirckheim 715. Guate- 

 mala City, Hitchcock 9051. 



Costa Rica: San CristSbal, WerckU 518. Alajuela, Jimenez 168, 703. Alto 

 del Rodeo, Pittier 1616. San Josg, Hitchcock 8502. 



Explanation of Plate 15. — Lasiacis rhizophora. Specimen from Coban, Guatemala, 

 Tiirckheim 715 (U. S. Nat. Herb. no. 975468). Natural size. 



7. Lasiacis leptostachya Hitchc, sp. nov. 



Plants forming a stout central cane, with numerous slender branches at the 

 nodes, clambering to the height of several meters ; main culms roughened and 

 somewhat cinereous with papillae and irregularly appressed hairs; floral 

 branchlets slender, conspicuously zigzag, smooth, 20 to 40 cm. long; sheaths 

 glabrous or nearly so, densely long-ciliate on the margin, hirsute on the 

 collar; ligule inconspicuous, about 0.5 mm. long; blades narrowly lanceo- 



