116 GRAMINEAE (GRASS FAMILY) 



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

 I 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 vnth viscid blotches ; branches spreading or ascend- 

 ing, spikelet-bearing to the base ; spikelets '2.(i 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 south w. 



69. P. scabriusculum 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 | 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 ^-i 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 south w. 



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 ivith 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-tiowered, 

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

 spik lets 3 mm. long, elliptical, minutely pubescent ; first glume ^-1 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 v/oods, D. C. and N. C. ; appar- 

 ently rare. 



■4- 14. Latifolia. Culms erect, stout ; blades 2 cm. or more wide, cordate-clasp- 

 ing at ixtse, strongly nerved, acuminate; ligule minute ; panicle open ; sjnke- 

 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 denselv 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 clandestinum ^^^^ ^^^^ short, the leaves crowded at the summit, the panicles 



Closed and open ^"tirely 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, mimitely 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. widf, rarely wider, i)ubescent beneath, sparsely so (rarely glal)rous) 

 above, short-ciliate un the margins toward the base; i)anicle 6-10 cm. long, 

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

 4-4.5 mrn. long, ob(Jvate ; first glume \-\ as long as the spikelet, second glume 



