HITCHCOCK AND CHASE GRASSES OF THE WEST INDIES, 297 



Trinidad specimens to T. paspaloides, the type of whicli we have not seen, 

 allowance is made for evident errors in the description and plate.^ The only 

 character described not readily to be explained is the long nerveless second 

 glume. In our specimens the second glume is shorter than the spikelet, the 

 midnerve apparent at the base only, the lateral nerves strong, the thin glume 

 readily splitting between them. The plant as a whole, however, well agrees 

 with tlie original description. 



Wet sandy savannas, Trinidad (Aripo Savanna, Hitclicock 10081; Piarco 

 Savanna, Hitchcock 10335), and Venezuela. Originally described from an island 

 in the Orinoco. This is the species described by Griesbach * as T. hirsuta. 



2. Thrasya robusta sp. nov. 



A cespitose perennial ; culms erect, rather stout, branching, 1 to 1.5 meters 

 tall, appressed-pubescent at and below the nodes ; sheaths scaberulous, ciliate, 

 villous at the throat and pubescent on the collar, the lower crowded, com- 

 pressed-keeled, sometimes strigose ; ligule a short firm membrane about 1 mm. 

 long ; blades flat or folded, firm, ciliate, glabrous but roughish beneath or some- 

 times sparsely puberulent, crisply puberulent above, 15 to 30 cm. long, 4 to 

 15 mm. wide, the upper smaller, those of the floral branches reduced to a short 

 point; racemes 1 (or occasionally 2), terminating the main culms and the 

 branches from the upper nodes, arcuate, 8 to 14 cm. long, the peduncles slender, 

 long-exserted, or the lower ones partly inclosed by the subtending sheath, 

 villous at the summit; the rachis 2 to 3 mm. wide, glabrous, not ciliate, the 

 margins curved upward embracing the base of the spikelets; spikelets oblong- 

 ellipsoid, 3.2 mm. long, 1.2 mm. wide, about as thick, in a single row, the 

 alternate ones facing in opposite directions, those of a pair being thus back 

 to back; first glume minute, hyaline, nerveless (an occasional nerved well- 

 developed glume found) ; second glume slightly shorter than the sterile floret, 

 5-nerved, rather crisply villous ; sterile lemma villous, subindurate, early 

 splitting down the center, the edges inrolled, subtending a staminate flower, 

 the palea firm on the margins, as long as its lemma ; fruit plano-convex, 2.8 

 mm. long, 1 mm. wide, elliptical, glabrous, minutely papillose, chartaceous, 

 not very indurate. 



Type in the U. S. National Herbarium, no. 865559, collected in a savanna at 

 St. Joseph, Trinidad, December 23, 1912, by A. S. Hitchcock (no. 10187). 



The only other specimen seen by us was collected in the wet sandy Piarco 

 Savanna, south of Arouca, Trinidad (Hitchcock 10352). 



30. MESOSETTJM Steud. 



inflorescence a single erect terminal spikelike raceme, the spikelets sub- 

 sessile, solitary, in two rows on one side of a slender rachis, the back of the 

 fruit turned from the rachis, ventricose on the side toward the rachis and 

 fitting into its concavities, the back of the spikelet flat or nearly so; glumes 

 and sterile lemma usually bearing stifE hairs on the strong lateral nerves, the 

 midnerve of the sterile lemma faint or suppressed; sterile palea wanting; 

 fruit ventricose on the palea side. 

 Racemes 6 to 12 cm. long; second glume (outer one) three-fourths as long as 



the spikelet 1. M. loliiforme. 



Racemes 3 to 4 cm. long ; second glume exceeding the spikelet 2. M. wrightii. 



^See Chase, Proc. Biol. Soc. Washington 24:112-114. 1911. 

 * Fl. Brit. W. Ind. 540. 1864. 



