116 GRAMINEAE (GRASS FAMILY) 



nodes bearded with reflexed hairs, a glabrous viscid ring below ; sheaths about 

 | as long as the internodes, the velvety pubescence wanting on the back toward 

 the summit, the naked surface viscid when fresh ; ligule 1 mm. long ; blades 

 rather thick, spreading, often reflexed in age, 1.2-2 dm. long, 1-1.5 cm. wide, 

 uppermost reduced ; panicle 1-1.5 dm. long, nearly as wide, many-flowered ; 

 axis, branches and pedicels with viscid blotches ; branches spreading or ascend- 

 ing, spikelet-bearing to the base ; spikelets 2.6 mm. long, obovate, turgid, papil- 

 lose-pubescent ; second glume shorter than the apiculate fruit. Culms leaning or 

 spreading in the autumnal state, repeatedly branching from the middle nodes, 

 the fascicles of branches usually fan-shaped and shorter than the very long 

 internodes, or elongated and scorpioid ; sheaths swollen above, constricted 

 at the throat. Wet ground, N. J. to I. T., and southw. 



69. P. scabriiisculum Ell. Culms 1-2 m. high, roughened at least below the 

 nodes, often puberulent ; sheaths loose, constricted and bearded at the throat, 

 densely papillose-hispid to nearly glabrous, often spotted ; ligule minute, mem- 

 branaceous, usually a ring of hairs above it ; blades stiffly ascending or spreading, 

 often reflexed, 1.5-2.5 dm. long, 9-12 (rarely 15) mm. wide, usually harsh- 

 pubescent beneath and glabrous above; panicle 1.2-2.5 dm. long, about f as 

 wide, rather densely flowered, the lower branches ascending, axis, branches and 

 pedicels prominently viscid-spotted, branches spikelet-bearing to the base ; spike- 

 lets 2.4 mm. long, ovate, acuminate, minutely puberulent; first glume \-\ as 

 long as the spikelet, second glume and sterile lemma exceeding the fruit. Autum- 

 nal state leaning or widely spreading, repeatedly branching from the middle 

 nodes ; branches erect, later ones short ; the crowded reduced blades often 

 harsh-pubescent on both surfaces. Swamps, W. Va., Va., and southw. 



70. P. aculeatum Hitchc. & Chase. Resembles the preceding; culms slender, 

 in very large clumps, scabrous, harsh-pubescent below; sheaths not so loose as 

 in the last, papillose-hispid with stiff sharp-pointed hairs, uppermost usually 

 glabrous ; ligule minute, membranaceous, ciliate ; blades stiffly ascending or 

 spreading, 1.2-2 dm. long, 9-15 mm. wide, very scabrous on the upper surface 

 and toward the apex beneath ; panicle 8-12 cm. long, about as wide, few-flowered, 

 axis and branches not viscid or with a few spots only, lower branches spreading ; 

 spikelets 3 mm. long, elliptical, minutely pubescent ; first glume \-\ as long as the 

 spikelet, second glume and sterile lemma slightly exceeding the fruit. Autum- 

 nal state somewhat spreading, branched from the middle nodes, the branches 

 divaricate, not much crowded. Swampy woods, D. C. and N. C. ; appar- 

 ently rare. 



t- 14. Latifblia. Culms erect, stout; blades 2 cm. or more wide, cordate-clasp- 

 ing at base, strongly nerved, acuminate ; ligule minute; panicle open; spike- 

 lets 3-4 mm. long, pubescent, strongly nerved. 



71. P. clandestinum L. Usually in very large clumps, 5-12 dm. high ; culms, 

 nodes and sheaths strongly papillose-hispid, or the upper nearly glabrous ; blades 



ascending, 1-2 dm. long, 1.8-2.5 cm. wide, scabrous toward 

 the ends ; panicle exerted, 1-1.5 dm. long, about as wide, 

 rather densely flowered, the fascicled branches ascending ; 

 spikelets 3 mm. long, elliptic, second glume shorter than the 

 subacute fruit. Autumnal state with appressed branches with 

 shortened internodes, the overlapping sheaths usually more 

 strongly papillose-hispid than the earlier ones, the later branch- 

 67 p i d r * e ^ s vei T short, the leaves crowded at the summit, the panicles 



Closed and open entirel y inclosed in the sheaths. (P. decoloratum Nash.) 

 spikelet x 3 Moist ground, Me. to Minn. , and southw. FIG. 67. 



72. P. B6scii Poir. Culms 3-7 dm. high, minutely pubes- 

 cent or glabrous, at least the lower nodes bearded with reflexed hairs ; sheaths 

 puberulent, a dense ring of pubescence at the summit ; blades 8-12 cm. long, 

 2.5-3 mm. wide, rarely wider, pubescent beneath, sparsely so (rarely glabrous) 

 above, short-ciliate on the margins toward the base ; panicle 6-10 cm. long, 

 usually nearly as wide, the lower branches spreading or ascending ; spikelets 

 4-4.5 mm. long, obovate ; first glume |-i as long as the spikelet, second glume 



