104 GEAMINEAB (GRASS FAMILY) 



7. P. MiLiXcEt'M L. (EUROPEAN MILLET.) Culms 2-5 dm. high, erect 01 

 decumbent ; sheaths papillose-hispid ; leaves 1-2.5 dm. long, 2.5 cm. or less 

 wide ; panicle dense, drooping at maturity ; spikelets ovoid, 5 mm. long, turgid. 



Waste places, Me. to Pa., westw. to Neb. (Adv. from Eu.) 



* * * DICHOTOMIFLORA. Branching annual, glabrous throughout. 



8. P. dichotomiflbrum Michx. Culms compressed, thick, suc- 

 culent, spreading or ascending from a decumbent base, 3-1 8 dm. 

 long ; leaves 24 dm. long, 8-15 mm. wide, scabrous above ; pan- 

 icles 1.2-4 dm. long, diffuse ; spikelets short-pediceled. mostly 

 secuud toward the ends of the branchlets, 3 mm. long, acute ; 

 first glume obtuse, second and sterile lemma pointed beyond 

 the fruit. (P. proliferum Am. auth. not Lam.) Low waste 

 florum '" grounds and cultivated fields, Me. to Neb., and southw. July- 

 Spikelet x 8. O ct - Slender, depauperate, erect or prostrate specimens occur 

 in sterile ground. FIG. 60. 



* * * * VIRG\TA. Stout simple mostly glabrous perennials, vrith long-pediceled 

 spikelets and stout creeping rootstocks. 



9. P. amarum Ell. Glaucous, caespitnse in large bunches, 5-15 dm. high; 

 leaves crowded at the base, involute, the uppermost exceeding the contracted 

 panicle, which is 4-8 dm. long, the long slender branches erect; spikelets 4.5 

 mm. long; first glume -f as long as the spikelet, second glume and sterile 

 lemma pointed beyond the grayish fruit. Sandy seashores, Va., and southw. 

 Aug. , Sept. Foliage bitter. 



10. P. amaroides Scribn. & Merr. Glaucous; culms 5-8 dm. high, scattered 

 from a stout creeping rpotstock ; leaves 1-3 dm. long, flat or somewhat involute; 

 panicle 1.5-4 dm. long, very narrow, the short branches appressed ; spikelets 6 

 mm. long; first glume as long as the spikelet or more. (P. amarum, var. 

 minor Vasey & Scribn.) Sandy seashores, Ct., and southw. Aug., Sept. 



11. P. virgatum L. (SWITCH GRASS.) Tufted, from strong creeping root- 

 stocks, 0.9-2 m. high, sometimes glaucous; leaves elongated, flat; panicles 1.5- 

 5 dm. long, nearly as wide, the branches ascending or spreading, 



naked at the base ; spikelets 4-4.5 mm. long ; the second glume 

 and sterile lemma spreading and pointed, exceeding the fruit. 

 Low open ground or salt marshes along the coast, also on prairies 

 in the interior, Me. to Man., and southw. Very variable ; leaves 

 sometimes pilose above near the base ; inarsh plants often very 

 luxuriant, with panicles 6 dm. or more long. FIG. 61. 



Var. obtusum Wood. More slender, 1 m. high or less; leaves 6 '- P-yirgatum. 

 not over 8 mm. wide ; panicle 1.5 dm. long or less, rather nar- 

 row; spikelets 3 mm. long; the second glume and sterile lemma blunt and 

 scarcely exceeding the fruit. (P. virgatum, var. breviramosum Nash.) Sand 

 barrens, N. Y., N. J., and southw, 



***** AoROSTofniA. Erect perennials; spikelets lanceolate, pointed, short- 

 pediceled along the elongated main branches of the panicle ; fruit narrowly 

 elliptical, exceeded by the second glume and sterile lemma. 



^-Rootstocks absent ; plants tufted from a short caudex, compressed at the leafy 



base, glabrous. 



12. P. longifblium Torr. Culms slender, 5-10 dm. high ; leaves flat or invo- 

 lute toward the ends, the uppermost often equaling the panicle, 3-5 mm. wide ; 

 panicle purplish, 1-2.5 din. long, rather few-flowered; branches solitary or in 

 2's, remote, very slender, finally spreading, naked at the base ; ynki'li'ts 2.8-3 

 mm. long ; first glume \ as long as the second which exceeds the sterile lemma. 



Moist sandy ground, Ct. to D. C., and southw., mostly coastal. July-Sept. 



13. P. agrostoides Spreng. Culms 4-10 dm. high, rather stout ; sheaths 

 loose ; blades 2-3.5 cm. long, flat. O.fi-1 cm. wide ; panicle often purplish, oblong- 

 ovate, 1.5-3 dm. long, the stiff branches ascending, naked at the base, with 



