656 MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



FIGURE 1451. Panicum cryp- 

 tanthum. Two views of 

 spikelet, and floret, X 10. 

 (Type.) 



FIGURE 1452. Distribution of 

 Panicum cryptanthum. 



15 cm long, 7 to 9 mm wide; panicle 6 to 10 cm long, the axis and 

 ascending branches viscid-spotted; spikelets 2.2 to 2.4 mm long, 

 lanceolate-elliptic, pointed. Autumnal culms erect, sparingly branch- 

 ing from the middle nodes, the panicles partly hidden in the sheaths. 

 9J. Low swampy ground, New Jersey; North Carolina to Florida; 

 Texas; rare (fig. 1452). 



16. Commutata. Culms relatively stout, glabrous or puberulent; 

 ligules obsolete or nearly so; blades cordate and more or less 

 cfliate at base; spikelets elliptic, not very turgid, 7- to 9-neryed, 

 pubescent. Autumnal culms usually rather sparingly branching. 

 103. Panicum ashei Pearson. (Fig. 1453.) 



Vernal phase usually purplish, from a knotted 



crown ; culms 25 to 50 cm tall, erect, stiff and wiry^ 



densely crisp-puberulent; 



sheaths less densely 



puberulent ; blades rather 



thick and firm, 4 to 8 cm 



long, 5 to 10 mm wide, 



glabrous; panicle 5 to 8 



cm long, loosely flowered; 



spikelets 2.4 to 2.7 mm 



long. Autumnal culms 

 erect or topheavy-reclining, bearing divergent branches from the 

 middle and upper-nodes or from the upper nodes only. 91 Dry, 

 especially rocky woods, Massachusetts to Michigan and Missouri, 

 south to northern Florida, Mississippi, and Oklahoma (fig. 1454). 



104. Panicum commutatum Schult. (Fig. 1455.) Vernal culms 

 40 to 75 cm tall, erect; sheaths glabrous or nearly so; blades 5 to 12 cm 



long, 12 to 25 mm wide, glabrous on both 

 surfaces or puberulent beneath; panicle 

 6 to 12 cm long; 

 spikelets 2.6 to 2.8 

 mm long. Autum- 

 nal culms erect or 

 leaning, branching 

 from the middle 

 nodes, the second- 

 ary branches 

 crowded toward 



the summit. 91 Woods and copses, 

 Massachusetts to Michigan and Mis- 

 souri, south to Florida and Texas (fig. 1456). 



105. Panicum mutabile Scribn. and Smith. (Fig. 1457.) Vernal 

 phase blue green, glaucous; culms solitary or few in a tuft, erect, 30 to 

 70 cm tall; sheaths glabrous; blades horizontally spreading, 6 to 15 

 cm long, 8 to 20 mm wide, tapering to both ends, glabrous, ciliate 

 toward the cordate base or the lower ciliate nearly to apex; panicle 7 

 to 15 cm long; spikelets 2.9 to 3 mm long. Autumnal culms erect or 

 reclining, sparingly branched from the middle and upper nodes. 

 9J. Sandy pine woods or hammocks, Coastal Plain, southeastern 

 Virginia to Florida and Mississippi (fig. 1458). 



106. Panicum joorii Vasey. (Fig. 1459.) Vernal culms 20 to 55 cm 

 tall, slender, spreading or ascending from a decumbent base, at least 



FWURE 1453. Panicum ashei. Two 

 views of spikelet, and floret, X 10. 

 (Type coll.) 



FIGURE 1454. Distribution of 

 Panicum ashei. 



