GRAMINE^E. 389 



HAB. Sandy barrens. N. J. to Flor. Get. U.Culm 12 

 feet high, terete. Flowers purple. Glume unequal. Scales ob- 

 ovate. 



11. A. mrginica Linn. : oulms numerous, procumbent at base, aa- 

 Burgent ; leaves subdistichous, involute, rigid ; panicles lateral and 

 terminal, spike-form ; the lateral ones concealed ; glume equal, about 

 as long as the pale. A. pungens Pursk. 



HAB. Sandy soils. N. Y. to Vir. Sept. Oct. CWmsafoot 

 high, hairy at base, with swollen sheaths. Anthers purple. 



12. A. longifolia Torr. : panicle contracted, spiked, generally con- 

 cealed ; paleae much longer than the glume, subequal, smooth and 

 spotless, without awns ; leaves very long, filiform and recurved at the 

 apex. 



HAB. Sandy fields. N, S. Sept. Oct. 24!. Culm 24 &et 

 high, simple, terete. Leaves 2 feet long. Panicle sometimes 

 exserted. 



13. A. clandestine, Spreng. : panicle spiked, partly concealed ; palese 

 unequal, much longer than the glume, hairy and spotted, slightly awn- 

 ed ; leaves very long. 



HAB. Dry hills. Penn. to Car. Sept. If. Culm 2 feet high, 

 terete. Panicle often sooty. Glume carinate. 



14. A. spica-venti Willd. : outer paleae with a very long straight awn; 

 panicle spreading. 



HAB. N. S. June. 0. Culm 18 inches high. Introduced. 



15. A. canina Willd. : culm prostrate, somewhat branching ; palew 

 with a recurved dorsal awn. 



HAB. Wet meadows. July. !. Introduced, 



2. TRICHODIUM. Mick. 



Glume 2-valved, 1-flowered. Palea 1, shorter than the 

 glumes, bearded and supported at the base by one or two fas- 

 sicles of hairs. Seed loose, covered by the paleafc. 



Triandria. Digynia. 



1. T. laxiflorum Mich. : culm erect ; leaves setaceous, and with the 

 sheaths somewhat scabrous ; panicle diffuse, capillary, with trichoto- 

 mous branches ; glumes unequal. Agrostis laxa Muhl.- 



HAB. Dry fields. Subarc. Amer. to Car. May, June. Zf. 

 Culm 18 inches high. Panicle at length much spread and loose, 

 pyramidal. Tldn Grass. 



2. T. scabrum Muhl. : culm geniculate at the base, assurgent, branch- 

 ed ; leaves linear-lanceolate, flat, striate, scabrous ; sheaths mostly 

 smooth ; panicle verticillate and divaricate ; glumes unequal ; palew 

 ovate, acute, 3-nerved. Jigrostris scabra Willd. 



HAB. Woods. N. S. Aug., Sept. U.Culm 12-18 inchet 

 high. Panicle diffuse, much branched, 



33* 



