MANUAL OF THE GRASSES OF THE UNITED STATES 



625 



unknown. % — Swamps, rare, western Florida, southern Alabama, 

 and Mississippi. 



6. Dichotoma. — Culms few to many in a tuft, glabrous, or only the 

 nodes pubescent; sheaths mostly glabrous or nearly so; ligules 

 minute; panicles open; spikelets 5- to 7-nerved. Autumnal culms 

 usually freely branching, leaves and panicles usually much re- 

 duced. 

 25. Panicum microcarpon Muhl. (Fig. 1310.) Vernal culms 

 tufted, erect or sometimes geniculate at base, 60 to 100 cm tall, the 

 nodes densely bearded with reflexed hairs; sheaths often mottled with 

 white spots between the nerves; blades spreading, the upper often 



Figure 1306. — Panicum bicknellii. Plant, X 1; 

 two views of spikelet, and floret, X 10. (Por- 

 ter, Pa.) 



Figure 1307.— Distribution of 

 Panicum bicknellii. 



Figure 1308.— Panicum cal/iphyllum. Two 

 views of spikelet, and floret, X 10. (Type.) 



Figure 1309.— Pani cu m nudicaute. 

 Two views of spikelet, and floret, 

 X 10. (Type.) 



reflexed, 10 to 12 cm long, 8 to 15 mm wide, glabrous, sparsely papil- 

 lose-ciliate at base; panicle many-flowered, 8 to 12 cm long; spikelets 

 1.6 mm long, elliptic, glabrous (rarely minutely pubescent). Autum- 

 nal phase much branched from all the nodes, reclining from the weight 

 of the dense mass of branches; blades flat, mostly 2 to 4 cm long. 

 % — Wet woods and swampy places, Massachusetts to Illinois, 

 south to northern Florida and eastern Texas (fig. 1311). 



26. Panicum nitidum Lam. (Fig. 1312.) Vernal culms tufted, 

 erect, 30 to 60 cm tall, the nodes bearded with reflexed hairs; upper 



