Genus ii. 



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. Fl. 



Erlang. 16. 1804. 

 Panicum glabrum Gaud. Agrost. 1 : 22. 181 1. 

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



1895. 

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



1 : 469. 1900. 

 Syntherisma Ischaemum Nash, N. Am. Fl. 17 : 151. 1912. 



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

 glabrous; leaves glabrous, the blades 1/-3' long, 

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

 narrowly linear, digitate or approximate at the sum- 

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

 1" long, in pair$, 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. Cam. Ed. 2, 1 : 52. 1772. 

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

 Paspalum sanguinale Lam. Tabl. Encycl. 1: 176. 1791. 

 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 a'-6' long, 2"-$" 

 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 ii" long, in pairs, elliptic- 

 lanceolate, acute, the first scale mmute, 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. 1 : 



226. 1827. 

 Panicum fimbriatum Link, Hort. Bot. Berol. 1 : 



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 i4'-8' long, 2"-s" wide, more or less 

 papillose-hirsute on both surfaces ; racemes 

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

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

 nute, the second scale 3-nerved, about i 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. 



