336 CONTRIBUTIONS FEOM THE NATIONAL HERBARIUM. 



Panicles many -flowered, usually 15 to 25 cm. or more long ; 

 branches straight or arcuate, not zigzag; blades mostly 

 over 1.5 cm. wide. 

 Spikelets 4.5 to 5 mm. long, on short stiff appressed 



pedicels 7. L. sloanei. 



Spikelets 3.5 to 4 mm. long, on flexuous pedicels. 



8. L. patentiflora. 

 Blades pubescent on one or both surfaces. 



Blades narrowly lanceolate, averaging 8 to 10 times as long as 



wide ; panicle large and open 9. L. sorg'hoidea. 



Blades ovate-lanceolate, usually 3 to 5 times as long as wide ; 

 panicle usually compact, rather narrow 10. L. ruscifolia. 



1. Lasiacis rugelii (Griseb.) Hitchc. Bot. Gaz. 51: 302. 1911. 

 Panicum rugelii Griseb. Cat. PI. Cub. 233. 1866. 



Prostrate, the main canes slender ; branches commonly fascicled, very leafy, 

 the pubescent sheaths overlapping, the small lanceolate firm puberulent, some- 

 what cinereous blades oblique at base ; panicles short-exserted, few-flowered. 



Rich woods, western Cuba, whence originally described, the type specimen 

 being Rugel 188 from Matanzas. Richard ^ refers this species to Panicum rusci- 

 folium H. B. K. 



2. Lasiacis grisebachii (Nash) Hitchc. Bot. Gaz. 51: 302. 1911. 

 Panicum grisebachii Nash, Bull. Torrey Club 35: 301. 1908. 



Stems more slender, freely producing rootlets, the long narrow blades not 

 crowded ; panicle branches ascending. 



Rich woods and shady banks, carpeting the floor of dark thickets, western 

 Cuba, whence originally described, the type specimen being Britton & Shafer 

 758 from Madruga. 



3. Lasiacis oaxacensis (Steud.) Hitchc. Proc. Biol. Soc. Washington 24: 145. 



1911. 



Panicum oaxacense Steud. Syn. PI. Glum. 1: 73. 1854. 



Slender, straggling, decumbent and geniculate at base, with numerous aerial 

 rootlets, the long branches ascending and arcuate, with narrow scabrous blades 

 commonly 20 cm. long, and large open few-flowered panicles, the spikelets borne 

 at the ends of the branchlets. 



Edges of woods, western Jamaica, Mexico, and Central America. Originally 

 described from Oaxaca. 



4. Lasiacis harrisii Nash, Torreya 13: 274. 1913. 



Climbing among bushes to a height of 5 meters or more, the main canes 

 Blender but strong, the very slender branches pendent, the young twigs com- 

 monly rosy purplish ; blades linear, thin, and lax ; panicles small, numerous, 

 short-exserted, or partly included. This species is more completely glabrous 

 than any other of the genus in the AVest Indies. 



Shaded slopes, mostly at higher altitudes, Jamaica (Blue Mountains), Porto 

 Rico (QuebradiUas, Maricao, and Cayey), and St. Jan. Originally described 

 from Jamaica, the type specimen collected at Cinchona by Delia Marble (no. 

 222). In Jamaica the species is found in the Blue Mountains at an altitude 

 of 1,000 to 1,500 meters ; in Porto Rico at an altitude of about 800 meters. 



5. Lasiacis divaricata (L.) Hitchc. Contr. U. S. Nat. Herb. 15: 16. 1910. 

 Panicum divaricatum L. Syst. Nat. ed. 10. 2: 871. 1759. 



Panicum Mmbusoides Desv. ; Hamilt. Prodr. PI. Ind. Occ. 10. 1825. 



In Sagra, Hist. Cuba 11: 307. 1850. 



