6. Panicum Ravenelii Scribn. & Merr. Fig. 152. 



Perennial; vernal culms fairly stout and erect, 3-7 dm. tall, densely papillose- 

 hirsute with ascending hairs, the nodes short-bearded; sheaths hirsute like the 

 culms; ligule a fringe or tuft 3-4 mm. long, on the larger leaves grading into 

 additional tuft at blade base; blades thick and firm, 8-15 cm. long, 1-2 cm. broad, 

 glabrous above, densely velvety-hirsute beneath; panicle 7-12 cm. long; spikelets 

 3.7-4.3 mm. long, sparsely papillose-pubescent, strongly 7- to 9-nerved: autumnal 

 phase more or less spreading, branching from the middle and upper nodes, the 

 short branches crowded at the summit. 



Sandy woodlands, in wet sandy loam, and in water and mud of lakes and ponds, 

 in Okla. (Cherokee and Haskell cos.) and e. and s.e. Tex., spring-fall; Del. to 

 Mo., s. to Fla. and Tex. 



7. Panicum scoparium Lam. Fig. 155. 



Perennial; vernal phase grayish-olive-green, velvety-pubescent throughout except 

 on a viscid ring below the nodes and at the summit of the sheath; culms 8-15 

 dm. long, stout, usually 2-3 (-4) mm. thick, erect or ascending, usually genicu- 

 late basally, sometimes scabrous below the nodes, sometimes puberulent; sheaths 

 glabrous or hispid, often mottled or white-spotted, commonly swollen basally and 

 contracted upward; ligule a fringe 0.5-1.3 (-1.4) mm. long (more than 1 mm. 

 long only in the best-developed leaves); blades rather thick, 12-25 cm. long, 9-18 

 mm. broad, often stiffish, ascending or spreading, glabrous or scabrous, sometimes 

 more or less pubescent beneath; panicle 8-20 cm. long, the axis and branches 

 with viscid blotches or these absent; spikelets 2.3-2.6 mm. long, ovate to obovate, 

 turg'd, papillose-pubescent to obscurely puberulent to glabrous, pointed (not 

 sharply), 7- to 9-nerved; autumnal phase erect, leaning or spreading, freely 

 branching from the middle and upper nodes, forming flabellate fascicles. P. 

 scabriusculum Ell. 



Sandy woodlands, usually in moist or even boggy areas, in swamps, marsh- 

 meadows, and wet soil along ditches, streams and about ponds, in Okla. (LeFlore 

 Co.) and e. and s.e. Tex., spring-fall; Mass. to Fla. w. thorugh Ky. to Mo., Okla. 

 and Tex.; Cuba. 



8. Panicum commutatum Schult. Fig. 153. 



Perennial; vernal culms erect or decumbent often from somewhat knotty bases, 

 25-75 cm. long, sometimes purplish-tinged; nodes never bearded; sheaths glabrous 

 or nearly so; ligule a minute scale or usually essentially absent; blades 5-10 (-15) 

 cm. long, (6-) 8-25 mm. broad, glabrous on both surfaces but often slightly 

 cordate and marginally ciliate near base; panicle 5-12 cm. long, loosely flowered, 

 not much or often incompletely exserted from the upper sheath; spikelets 2.4-3.1 

 mm. long, 7- to 9-nerved, pubescent, ellipsoid, not very turgid; autumnal culms 

 erect or leaning, often widely spreading, not much-branched, the winter rosette 

 leaves often with a minute cartilaginous margin. P. Joorii Vasey, P. Ashei Pearson. 



Low or swampy woods in Okla. (Waterfall) and e. Tex.; e. U.S. w. to Mo., 

 Okla. and Tex.; Mex. 



9. Panicum geminatum Forsk. Fig. 156. 



Perennial, glabrous; culms terete, tufted, 25-80 cm. long, rarely decumbent 

 basally and rooting at the nodes, usually slightly geniculate basally and essentially 

 erect; blades 1-2 dm. long, 3-6 mm. broad, flat or toward the apex involute; 

 panicle 12-30 cm. long, extremely narrow; appressed spikelike racemes (3 to) 

 8 to 18, lower racemes 25-30 mm. long, upper gradually shorter; raceme rachis 

 ending in a short naked point; spikelets 2.2-2.4 mm. long, 5-nerved, subsessile, 

 abruptly pointed, glabrous, the first glume truncate; fertile lemma and palea 



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