HITCHCOCK AND CHASE GRASSES OF THE WEST INDIES. 277 



1. Trachypog-on gouini Fourn. Mex. PI. 2: 66. 1886. 



A tall slender glabrous unbranched perennial, usually geniculate below, spar- 

 ingly producing scaly rhizomes ; blades involute, the narrow pale feathery 

 raceme up to 30 cm. long. 



Open ground in the vicinity of Habana, Cuba, introduced from eastern Mexico. 

 Originally described from Veracruz. 



2. Trachypogon filifolius (Hack.) Hitchc. Contr. U. S. Nat. Herb. 12: 191. 



1909. 

 Trachypogon polytnorphus var. filifolius Hack, in Mart. Fl. Bras. 2': 264. 1883. 

 More slender than the preceding, without rhizomes, the raceme with coarser 

 shorter less feathery awns. 



Sandy pine woods, western Cuba ; also in Brazil, whence originally described. 



3. Trachypog'on plumosus (Humb. & Bonpl.) Nees, Agrost. Bras. 344. 1829. 

 Andropogon plumosus Humb. & Bonpl. ; Willd. Sp. PI. 4: 918. 1806. 

 Trachypogon polymorphus var. plumosus Hack, in Mart. Fl. Bras. 2': 265. 1883. 

 Usually stouter than the other two, the culms sparingly branching, the blades 



flat, the spikes commonly 2 or 3. 



Wet sandy savannas, Central America to Brazil. Originally described from 

 Cumana, Venezuela. 



Trinidad (Piarco Savanna, Hitchcock 10342; St. Joseph, Hitchcock 10185, 

 ind Arima, Eggers 1379). 



11. ARTHRAXON Beauv. 



Perfect spikelets awned, sessile, the secondary spikelet and its pedicel want- 

 ing or present only at the lower joints of the filiform articulate rachis ; racemes 

 terminating the branches of a dichotomously forking panicle, in appearance sub- 

 digitate or fascicled. 



1. Arthraxon quartinianus (A. Rich.) Nash, N. Amer. Fl. 17: 99. 1912. 



Alectoridia quartiniana A. Rich. Tent. Fl. Abyss. 2: 448. 1852. 



Arthraxon ciliaris subsp. quartinianus Hack, in DC. Monogr. Phan. 6: 356. 

 1889. 



A weak-stemmed, laxly branching creeping annual, with ascending flowering 

 branches, bearing flat thin ovate blades cordate at base and flabellate fascicles 

 of slender spikes. 



Shady banks, Jamaica and Guadeloupe, introduced from tropical regions of 

 the Old World. Originally described from Abyssinia. 



12. ANDROPOGON L. 



Sessile spikelet perfect, usually awned ; pedicellate spikelet staminate or 

 neuter ; rachis articulate ; racemes solitary, digitate, or approximate along a 

 continuous main axis. The species with woolly inflorescence are often called 

 " barba de indio " in the Spanish islands. In the English islands Andropogon 

 bicomis and A. glomeratus are called " foxtail." 



Sterile or pedicellate spikelets as large as the perfect ones or larger, imbricate ; 

 racemes mostly single. (See also A. pertusus and A. annulatus with 

 several racemes.) 

 Plants annual ; outer glume of sterile spikelet large, bractlike, partly con- 

 cealing the perfect spikelets 1. A. fastig'iatus. 



Plants perennial ; sterile spikelets not much larger than fertile ones, not 

 concealing them. 



Peduncle glabrous below the raceme 10. A. caricosus. 



Peduncle pubescent below the raceme 11. A. uodosus. 



