16 POACEAE. 



2. Syntherisma digitata (Sw.) Hitchc. Contr. U. S. Nat. Herb. 12: 142. 1908. 



Milium digitatum Sw. Prodr. 24. 1788. 

 Digitaria horisontalis Willd. Enum. 92. 1809. 

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

 Syntherisma setosa Nash, Bull. Torrey Club 25: 300. 1S98. 



Culms 4-10 dm. long, branched, tufted, at length decumbent below and 

 rooting at the lower nodes. Leaves more or less densely hirsute, 2-12 cm. 

 long, 2-7 mm. wide ; racemes several, 3-14 cm. long, whorled or alternate or ap- 

 proximate in pairs, widely spreading; rachis very narrow; spikelets in pairs, 

 about 2.5 mm. long, lanceolate, acuminate ; first scale minute, glabrous ; second 

 scale 3-nerved, appressed-pubescent; third scale 7-nerved, also appressed- 

 pubescent ; fruiting scale nearly 2 mm. long, shorter than the third, elliptic, 

 greenish when mature. 



Sandy places and cultivated ground, Berry Islands, Andros, New Providence, 

 Great Exuma, Eleuthera, Wntling's Island, Long Island : Florida ; throughout 

 tropical America. SOUTHERN CRAB-GRASS. 



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



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



Digitaria sanguinalis Scop. Fl. Cam. ed. 2, 1: 52. 1772. 



Digitaria marginata Link, Enum. Hort. Berol. 1: 102. 1821. 



Digitaria fimlriata Link, Hort. Berol. 1: 226. 1827. 



Panicum fimbriatum Kunth, Eev. 33. 1829. 



Syntherisma marginatum Nash, N. A. Fl. 17: 154. 1912. 



Culms 8 dm. long or less, finally branched, prostrate at the base and root- 

 ing at the lower nodes. Lower leaf-sheaths densely papillose-hirsute ; blades 

 2-8 cm. long, 5-10 mm. wide, erect or ascending, glabrous or more or less 

 pubescent; racemes 2-9, 2-12 cm. long, erect or ascending, alternate, in pairs 

 or whorls ; spikelets 3-3.5 mm. long, about 0.8 mm. wide, lanceolate, very acute, 

 in pairs; first scale small, glabrous, the second and third appressed-pubescent 

 with long hairs, the second one 3-nerved, the third slightly exceeding the flower- 

 ing scale, 7-nerved, the pubescence usually becoming widely spreading, the 

 fourth one lanceolate, very acute, yellowish white at maturity. 



Sandy places, roadsides and waste places. Great Bahama, Ahaco, New Provi- 

 dence, Eleuthera, Long Island, Elbow Cay, Fortune Island, Acklin's Island. Inagua : 

 temperate and tropical America. Native of the Old World. Referred by Hitch- 

 cock to Panicum Linkianum Kth. LARGER CRAB-GRASS. 



S. VALOTA Adans. Fam. PI. 2: 495. 1763. 



Tall perennial grasses, with flat leaves and large terminal pubescent pan- 

 icles. iSpikelets lanceolate, acute or acuminate ; scales 4, the 3 outer ones 

 membranous, empty, the first minute or rudimentary, the second silky-pilose 

 and dilate, the fourth one shorter, glabrous, shining, chartaceous. [Perhaps 

 in honor of P. Vallot.] Several species, of warm temperate and tropical Amer- 

 ica, the following typical. 



1. Valota insularis (L.) Chase, Proc. Biol. Soe. Wash. 19: 188. 1906. 



Andropogon insulare L. Syst. Nat. ed. 10, 1304. 1759. 

 Panicum leucopliacum H.B.K. Nov. Gen. & Sp. 1: 97. 1815. 

 Panicum insulare Meyer, Prim. Fl. Esseq. 60. 1818. 

 Tricliacline insularis Nees, Agrost. Bras. 86. 1829. 



Culms erect, slender, 1-1.6 m. high, clustered. Leaves 3 dm. long or less, 

 1-2 cm. wide, acuminate, glabrous or their sheaths pubescent ; panicle narrow, 

 often 3 dm. long, little, if any more than 3 cm. thick; spikelets 4-6 mm. long, 



