282 



Bulletin No. 205 



[March, 



Eachis ■with the lateral angles winged; culms spreading, often rooting at the 

 lower nodes. 



Pedicels sharply 3-angled ; first glume present ; sheaths densely pubescent. 



S. sanguinalis 



Pedicels rounded; first glume wanting; sheaths smooth. S. ischaemum 



Raehis with wingless angles; culms erect, never spreading and rooting at the lower 



nodes. S. fiUformis 



1 80 



Figs. 29-32. — 29, S. ischaemum, inflorescence; 30, S. filiformis, group of spike- 

 lets; 31, (S'. ischaemum, group of spikelets; 32, S. sanguinalis, group of spikelets 



Syntherisma filiformis (L.) Nash 

 Slender Finger Grass (Fig. 30) 



Digitaria -filiformis, Engelmann '44, 103. Panicum fiUforme, Lapham '57, 

 548, 593; Patterson '76,52; Flagg '78, 284; Brendel '87, 88. Syntherisma fili- 

 formis, Gleason '07, 181. Digitaria filiformis, Gleason '10, 147. 



Culms 6 to 28 inches long, erect ;; leaves short, grouped at the base 

 of the plant; at least the lower sheaths pubescent; racemes 2 to 5, 

 generally erect; spikelets pubescent, 1.7 to 1.8 mm. long, mostly in 

 threes. 



This grass is found in dry, sandy soil, usually along roadsides 



and in waste places. It is not abundant in Illinois. 



ILLINOIS SPECIMENS: Without locality, M. S. Bebb in 1860. christian CO. 

 Taylorville, Andrews, July, 1898. menard co. Without locality. Hall; Athens, 

 Hall, Sept., 1866. ST. clair co. Without locality, Brendel in 1850; Mascoutah, 

 Welsch. WABASH CO. Without locality, Shearer. 



rs 



Syntherisma ischaemum (iSchreb.) Nash 

 Small Crab Grass. Smooth Crab Grass (Figs. 29 and 31) 



Panicum glabrum, Lapham '57, 548, 593; Babcock '73, 97; Patterson '76, 

 52; Flagg '78, 284; Higley and Eaddin '91, 139; Huett '97, 128. Syntherisma 

 linearis, Britton '07, 77. Digitaria humifusa, Gray's Manual, 7th ed., p. 95. 



Culms G to 24 inches long, spreading over the ground, often rooting 



at the lower nodes and forming large mats; sheaths and blades smooth 



and glabrous ; racemes 2 to 5, usually 3 ; spikelets glandular pubescent 



between the nerves, 2 to 2.2 mm. long, usually in threes, on rounded 



pedicels ; first glume wanting. 



