HITCHCOCK AITD CHASE GRASSES OF THE WEST INDIES. 293 



Second glume as long as the dark fruit ; spikelets pubescent. 



3. S. isChaemum. 

 Second glume shorter than the fruit; spikelets minutely pubescent or 

 subglabrous. 

 First glume small but distinct ; spikelets about 3 mm. long. 



2. S. sanguinalis. 

 First glume obsolete ; spikelets less than 2.5 mm. long. 



Plants prostrate, forming mats ; blades pilose ; fruit pale. 



5. S. serotina. 

 Plants erect or ascending ; blades glabrous or nearly so ; fruit 



black 6. S. longiflora. 



Ilachis not winged. 



Second glume and sterile lemma equal ; fruit pale ; spikelets glabrous or 



nearly so 4. S. simpsoui. 



Second glume shorter than the sterile lemma and fruit. 



Ilachis sparsely beset with scattered spreading long hairs ; fruit pale. 



1. S. digitata. 

 Rachis with no long hairs ; fruit brown. 



Spikelets glabrous 8. S. curvinervis. 



Spikelets with stripes of dense silky hairs. 



Spikelets 2.5 to 3 mm. long, with copious long silky hairs ex- 

 tending beyond the apex of the spikelet. 



10. S. leucocoma. 

 Spikelets 1.5 to 2 mm. long. 



Hairs on the spikelet extending beyond the apex as a stiff 



brushlike tip 12. S. argillacea. 



Hairs on spikelet not brushlike at tip and not extending 

 beyond the spikelet. 



Blades villous 11. S. villosa. 



Blades glabrous or nearly so 9. S. panicea. 



1, Syntherisma digitata (Swartz) Hitchc. Contr. U. S. Nat. Herb. 12: 142. 



1908. 



Milium digitatum Swartz, Prodr. Veg. Ind. Occ. 24. 1788. 



Digitaria horizontaUs Willd. Enum. Hort. Berol. 92. 1809. 



Axonopus digitatus Beauv. Ess. Agrost. 12, 154. 1812. 



Digitaria setigera Roth; Roem. & Schult. Syst. Veg. 2: 474. 1817. 



Panicum Jiorizontale Meyer, Prim. Fl. Esseq. 54. 1818. 



Digitaria setosa Desv. ; Hamilt. Prodr. PI. Ind. Occ. 6. 1825. 



Digitaria jamaicensis Spreng. Syst. Veg. 1: 272. 1825. 



Paspalum digitatum Kunth, Rev. Gram. 1: 24. 1829. 



Panicum hamiltonii Kunth, Enum. PI. 1: 84. 1833. 



Syntherisma setosa Nash, Bull. Torrey Club 25: 300. 1898. 



A decumbent branching stoloniferous weedy annual with pilose sheaths and 

 pubescent, often velvety, flat blades, and 5 to 15 very slender lax racemes up to 

 8 cm. long, subdigitate or in fascicles along a slender axis. 



A common weed in fields, open ground, and waste places, tropical regions of 

 both hemispheres. Originally described from Jamaica ; the type of Digitaria 

 jamaicensis also from Jamaica. Digitaria setosa and Panicum hamiltonii were 

 described from the Antilles ; Digitaria setigera from India ; DigitaiHa horizontaUs 

 from Santo Domingo. To be found in probably all of the West Indian islands. 

 This is sometimes called in Cuba " pata de gallina fina " (fine henfoot). 



2. Syntherisma sanguinalis (L.) Dulac, Fl. Haut. Pyr. 77. 1867. Ckabgrass. 

 Panicum sanguinale L. Sp. PI. 57. 1753. 



Digitaria sanguinalis Scop. Fl. Carn. ed. 2. 1: 52. 1772. 



