86 TRIANDRIA. DIGYNIA. aorostis. 



Schult. II. p. 346. A, decumbens Muhl. Gram, 



p. 68. 

 Eoot creeping. Culm assurgent, geniculate at the base and fre- 

 quently throwing out runners. Leaves nervose, scabrous, 

 about 2 lines wide. Stifiuie white and membranaceous, acu» 

 minale. Panicle with the branches at length horizontal, but 

 not divaricate. Glumes of the calyx equal, scabrous on the 

 keel. Corolla shorter than the calyx. Stamens 3 ; anthers 

 yellow. 

 Hab. In fields and pastures; common. June — August. In- 

 troduced. 



The A. decumbens o{ Muhlenberg differs so little from 

 A. alba, that I have concluded to refer it to this species. It 

 appears to be nothing more than the A. stolonifrra, or Fiorin- 

 grass of the English botanists, which grass Hooker^ with 

 much propriety, considers only as a variety of A. alba. 



4. A. lateriflora Mich: culm erect, branched above, 

 soboliferous at the base ; panicle lateral and terminal, con- 

 tracted, dense : calyx acuminate ; corolla longer than the 

 calyx, equal, pubescent at the base, awnless. Mich. Fl. I, 

 p. 53. Pursh Fl. 1. p. 64. R o e m. ^ S chut t. II. 

 p. 353. A. mexicana M ii h L Gram, p. 67. nee L.et JVilld, 

 Trichochlo^ ? sp. Trin. 



Root perennial, creeping. Culm 2 feet or more high, with nu- 

 merous swelling nodes, frequently naked below ; branches 

 erect. Leaves broad-linear, flat, scabrous on the margin and 

 upper surface. Sheaths compressed. Stifiule short, obtuse 

 and lacerate. Panicles terminating the branches, dense and 

 spike-form, a little secund ; the lateral ones partly sheathed at 

 the base ; branches alternate and fasciculate. Glumes of the 

 calyx very acute, rough at the keel. Corolla generally as long 

 again as the calyx, very acute ; inferior valve 3-nerved, rarely 

 with a short awn at the tip. Stamens 3 ; anthers pale purple. 

 Siigmas purple. iSeed oblong. 



Hab. In swamps, wet meadows, borders of woods, 8cc. Massa- 

 chusetts to Pennsylvania. August — September. 



This grass differs from the A. mexicana L. in having a less 

 branched culm, the corolla longer than the calyx, &c. The 

 A. Cinna oi P e t z, which fVi lldenoiv places as a synonym 

 of his A. mexicana, is monandrous. 



0. filiformis*: panicles very slender; corolla nearly 

 equalling the calyx. A. jiliformis Muhl. Gram. p. 66. 

 Willd. Enum. h. Berol. I. p. 95. A. foliosa Roem. ^ 

 SchulU II. p. 373. Trichochloa ^/j/brmis Trin. 



Whole plant more slender than the preceding; leaves nar- 

 rower. According to Mu hlenb erg, it varies with a pro- 

 cumbent culm, and the glumes of the calyx unequal and some-- 

 what awned. 



