GENUS u. 



GRASS FAMILY. 



123 



4 . Syntherisma Ischaemum (Schreb.) Nash. Small Crab-grass. Fig. 281. 



Panicum lineare Krock. Fl. Sil. i : 95- 1787- Not L. 

 Panicum Ischaemum Schreb.; Schweigger, Spec. 



Erlang. 16. 1804. 



Panicum glabrum Gaud. Agrost. i: 22. 1811. 

 Syntherisma linearis Nash, Bull. Torr. Club 22: 420. 



Syntherisma humifusum Rydb. Mem. N. Y. Bot. Card. 



I : 469. 1900. 

 Syntherisma Ischaemum Nash, N. Am. Fl. 17 : 151- l< ) 12 - 



Culms erect or decumbent, i-2 long, smooth and 

 glabrous; leaves glabrous, the blades i'-3' long, 

 i "-2" wide, acuminate; racemes 2-6, 2 '-4' long, 

 narrowly linear, digitate or approximate at the sum- 

 mit of the culm; rachis flat, winged; spikelets about 

 i" long, in pairs^ sometimes in 3's ; first scale rarely 

 present, second and third as long as the fourth. 



In cultivated grounds and waste places, Nova Scotia 

 to South Dakota, south to Florida and Kansas. Nat- 

 uralized from Europe. July-Sept. Smooth Finger-grass. 



5. Syntherisma sanguinale (L.)Dulac. Large Crab-grass. Finger-grass. Fig. 282. 



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

 Digitaria sanguinalis Scop. Fl. Carn. Ed. 2, i : 52. I77 2 - 

 Syntherisma praecox Walt. Fl. Car. 76. ' 1788. 

 Paspaliim sanguinale Lam. Tabl. Encycl. i: 176. I79 1 - 

 Syntherisma sanguinale Nash, Bull. Torr. Club, 22 : 



420. 1895. 



Culms erect or decumbent, often rooting at the 

 lower nodes, i-3 long, smooth. Sheaths, at least 

 the lower, papillose-hirsute; blades 2'-6' long, 2"-s" 

 wide, acuminate, more or less pubescent; racemes 

 3-10, narrowly linear, 2 '-6' long, digitate or in ap- 

 proximate whorls at the summit of the culm; rachis 

 flat, winged; spikelets \\" long, in pairs, elliptic- 

 lanceolate, acute, the first scale minute, rarely want- 

 ing, the second one-third to one-half as long as the 

 spikelet, 3-nerved, the third 7-nerved. 



In cultivated or waste places, throughout North 

 America, except the extreme north. Naturalized from 

 Europe. Widely distributed as a weed in all cultivated 

 regions. July-Aug. Hairy Finger-grass ; Crowfoot or 

 Pigeon-grass. 



6. Syntherisma marginatum (Link) 

 Nash. Fringed Crab-grass. Fig. 283. 



Digitaria marginata Link, Enum. Hort. Berol. i : 



226. 1827. 

 Panicum fimbriatum Link, Hort. Bot. Berol. i : 



226. 1827. 

 Syntherisma fimbriatum Nash, Bull. Torr. Club 



25 : 302. 1898. 

 Syntherisma marginatum Nash, N. Am. Fl. 17: 



154. 1912. 



Culms 3 long or less, finally prostrate at the 

 base and rooting at the lower nodes ; sheaths, 

 at least the lower, densely papillose-hirsute; 

 blades ii'-S' long, 2 "-5" wide, more or less 

 papillose-hirsute on both surfaces ; racemes 

 3-10, 2'-7' long; spikelets \\" long, elliptic- 

 lanceolate, acute, in pairs, the first scale mi- 

 nute, the second scale 3-nerved, about \ as 

 long as the spikelet, the third scale 7-nerved. 



Dry sandy soil, Maryland to Kansas, south to 

 Florida and Texas. Also in tropical America. 

 June-Sept. 



