ORDER 156. GRAMINE^E. 797 



base, compressed, 3 to 8' ; Ivs. lance-linear, short, smooth, carinate, on loose, 

 glabrous sheaths ; slip, oblong, dentate ; panicle spreading, the branches gener- 

 ally solitary, at length horizontal ; spikelets ovate-oblong, rather numerous, con- 

 taining about 5, loose flowers. -CD A small, abundant, annual grass, Can. and 

 U. S., forming a dense, soft and beautiful turf. May Sept. 



2 P. flexuosa Muhl. Culm erect from a tufted base, 12 to 20' ; Ivs. 2 to 5' by 1 

 to 2^'', gradually acute ; upper half of the culm naked, bearing a thin, open pan. ; 

 lranch.es mostly in pairs, filiform, often flexuous, long (2 to 3'), with the few 

 pedicellate spikelets at the end ; fls. 3 or 4, lanceolate, scarious-pointed, pubes- 

 cent but not webbed at base, the gls. about as long (2J"). y Woods, Va., 

 Ky. to Ga. Spikelets not purplish. Apr. Jl. (P. autumnalis Muhl.) 



8. SCARIOSA. Fls. of the spikelet 4 to 6, narrowly lanceolate, remote, nearly 

 glabrous, with conspicuously scarious (blunt) points. E. Tenn. 



3 P. hexantha. Culm weak and slender, 18 to 24', erect from the decumbent 

 lower joint ; Ivs. 3 to 5' long, very gradually attenuated, the upper reaching the 

 panicle which is very open, the branches in pairs, long (2 to 4'). bearing the long 

 pediceled spikelets near the end; spikelets oblong (4"), mostly G (5 to 1)-flowered, 

 fls. remote, oblong, villous (not webbed) at base, very obtuse and compressed at 

 the scarioua apex. U Found at Atlanta, Ga., in meadows, perhaps a foreigner. 

 Spikelets few but large. Jn. 



4 P. dinantha. Culms in dense tufts, very slender, 18' to 2f, from fibrous roots ! 

 Ivs. narrowly linear, about 3' by 1", soon reflexed, sheaths rather shorter; ligule 

 short, truncate; pan. very slender and few-flowered, branches erect, very few, 

 solitary or 2 together; spikelets 2 or 3 (mostly 2)-flowered; fls. acute, obscurely 

 veined, smooth, except the copious web at base, the acute glumes much shorter. 

 Fields, Montgomery, Ala. May, Jn. 



5 P. brevifolia Muhl. Culm compressed, 1 to 2f ; Ivs. of the culm about 2, flat, 

 oblong, cuspidate and pungent, lower about l' long, upper 6", root Ivs. long and 

 narrow, all erect, keeled and pungent at the point ; ligule truncate, lacerate ; 

 sheaths nearly as long as the nodes ; pan. loose, branches filiform, in pairs ; spike- 

 lets ovate, 3 to 4-flowered ; fls. rather obtuse, Z\" long, slightly webbed. If Penn. 

 (Jackson) to Va. and 111. Spikelets often tinged with purple. Apr., May. (P. 

 pungens Nutt. P. cuspidata Bart.) 



6 P. debilis Torn Culm erect 18' to 2f; Ivs. lance-linear, flat, gradually acute ; 

 ligule oblong, acute; pan. loose, few-flowered, some spreading, branches mostly in 

 pairs, flexuous ; spikelets ovate, obtuse ; 3 (rarely 2)-flowered ; fls. very obtuse, 

 \\" long, faintly 3-veined, webbed at base; palea green; glumes ovate, acute. 

 Eocky woods, Conn, to III 



7 P. laxa Hcenke. Culm csespitous, 6 8'; Ivs. linear, acute, erect; stip. lanceo- 

 late; pan. 1 2' long, contracted, nodding, branches mostly in pairs, smooth, 

 flexuous; spikelets 2J'' long, ovate, 3-flowered; fls. often purple, acute, hairy, 

 somewhat webbed at base; glumo lance-ovate, slightly scabrous on the keel; 

 lower palea hairy below, upper rough-edged ; anth. violet. It Mountains N. Eng. 

 and N. Y. to Arc. Am. 



8 P. alpina L. Culms erect, 6', from fibrous roots; Ivs. short, broadly linear, 

 obtuse, lower with short, truncate ligules, upper with oblong, acute ones; pan. 

 equal-sided, erect, ovate or oblong, loose, the branches in pairs, spreading, with 

 rather large, ovate, short-pediceled, 5 (4 to 9)-flowered spikelets; fls. ovate. 

 Can. West and high northward. Jn. 



9 P. compressa. BLUE GRASS. Culm decumbent and rooting at base, much com- 

 pressed, 12 18'; Ivs. linear, short, bluish green; sheaths rather loose, with a 

 short, obtuse stipule; pan. contracted, 3' by 1 or less, somewhat secund, branches 

 very short, in 2s and 3s; spikelets ovfite-oblong. flat, 3 to 7-flowered, subsessile, 

 fls. rather obtuse, webbed. A valuable grass, with sweet and nutritious herbage, 

 propagating itself everywhere (Va., Tenn., northward) in woods, pastures and 

 meadows. May, Jn. (a month later than P. pratensis). 



10 P. sylvstris Gray. Culm erect, compressed, 2 to 3f; Ivs. flat, soft, 3 to G' 

 long, 1 to 2" wide, gradually attenuated; ligules blunt; pan. oblong-pyramidal, 

 thin, branches in 5s or more, flexuous, 1 to 2' long, spikelets (2") pedicellate, 

 broad-ovate, 2 or 3-flowered ; fls. oblong, obtuse, copiously webbed. Kocky woods, 



