POACEAE. 



19 



1. Syntherisma sanguinsllis 

 (L.) Dulac. Common Crab- 

 grass. (Fig. 22.) Culms 2i° 

 long or less, finally branched, 

 prostrate at the base and root- 

 ing at the lower nodes. Lower 

 leaf-sheaths densely papillose- 

 hirsute; blades 2"-5" wide, 

 erect or ascending, glabrous or 

 more or less pubescent: racemes 

 2-9, l'-5' long, erect or ascend- 

 ing, alternate, in pairs or 

 whorls; spikelets about 1*" 

 long, lanceolate, very acute, in 

 pairs; first scale small, gla- 

 brous, the second and third ap- 

 pressed-pubescent with long 

 hairs, the second one 3-nerved, 

 the third slightly exceeding the 

 flowering scale, 7-nerved, the 

 pubescence usually becoming 

 widely spreading, the fourth 

 one lanceolate, very acute, yel- 

 lowish-white at maturity. [Pan- 

 icum lineare of Lefroy; Pani- 

 cum sanguinale L. ; Digitaria 

 marginata Link ; Syntherisma 

 marginatum Nash.] 



Common in waste and cultivated grounds, often a pernicious weed. Naturalized. 

 Southern United States ; Bahamas ; tropical South America. The characters relied 

 upon by authors to separate S. marginatum from S. sanguinale do not appear to be 

 specific. 



2. Syntherisma d i g i t a t a (Sw. ) 

 Hitchc. Narrow Crab-grass. (Fig. 23.) 

 Culms lh°-2>° long, branched, tufted, at 

 length decumbent below and rooting at 

 the lower nodes. Leaves more or less 

 densely hirsute, l'-5' long, l"-3i" wide; 

 racemes several, IV-^Y long, whorled or 

 alternate or approximate in pairs, widely 

 spreading; rachis very narrow, spikelets in 

 pairs, about 1" long, lanceolate, acuminate; 

 first scale minute, glabrous; second scale 

 3-nerved, appressed-pubescent ; third scale 

 7-nerved, also appressed-pubescent ; fruit- 

 ing scale nearly 1" long, shorter than 

 the third, elliptic, greenish when mature. 

 \Milium digitatum Sw.; Digitaria sctigcra 

 Roth; Panicum Jiorizontale Meyer.] 



Bermuda (according tc Lefroy, and North 

 American Flora 17: 154). Florida; West In- 

 dies ; tropical continental America. 



