GRAMINE^. (grass FAMILY.) 593 



* * Spikes 2, and in pairs, rarely 4, or more, lioarij with long spreading hairs, 

 the peduncle sheathed by a leaf-like bract : sterile flower a single glume, or 

 obsolete. 



1- Bract mostly shorter than the peduncle, its blade very short or none (in No, 7 



variable). 



7. A. Elliottii, Chapiii. Culms 2°- 3° high, bearded at the upper joints, 

 the brauches short aud simple ; leaves narrow-linear, the lower sheaths hairy, 

 the upper smooth and mostly densely crowded and enlarged ; spikes 2 (rarely 

 4), long-exserted, or included in the upper sheaths, loosely 8 - 10-flowered, 

 the hairs long and glossy ; glumes scabrous, 2|" long, one third as long as the 

 straight awn. — Dry pine barrens. Sept. 



8. A. arctatUS, Chapm. Culm single (2° -5° high), the appressed 

 branches narrowly paniculate ; leaves aud sheaths shaggy wii^h long white, 

 mostly deciduous hairs; spikes by pairs (I'-l-J' long), rather stout, closely 

 15-20-flowered ; glumes rough, twice as long as the joints of the rachis; 

 hairs of the rachis few and short; stamen 1. — Low pine barrens, Florida. 

 Sept. - Oct. 



9. A. argyrseus, Schultes. Glabrous and more or less glaucous ; culms 

 2° high ; branches simple, erect, the lower single, the upper in pairs, bearded 

 below the upper joints ; leaves linear, 6-8 long ; spikes 2, 1 J' - 2' long, 10-12- 

 flowered, densely villous, the stout peduncle closely enwrapped by the leafless 

 bract ; glumes 2^" long, smooth, nerveless, longer than the rigid very villous 

 joints of the rachis ; awns 1' long ; stamens 3. — Dry soil in the lower districts. 

 Sept. - Oct. 



1 0. A. Cabanisii, Hackel. Habit and most of the characters of the pre- 

 ceding, but the .<pikes narrower and 10- 15-flowered, the rachis less villous, 

 with shorter hairs ; lower glume scabrous, and faintly nerved ; awns Y long. 

 South Florida (Garber). 



■*- t- Bract longer than the peduncle (except No. 15), its blade mostly longer than 



the spikes. 



11- A. longiberbis, Hackel. Culms 2° high, loosely paniculate above 

 the middle ; leaves linear, smooth, 5' - 10' long, the lower sheaths appressed- 

 pubescent ; spikes 2, rather rigid, closely 10- 12-flowered, shorter than the 

 bracts, the straight raciiis densely villous with long spreading hairs ; glumes 

 2" long ; pedicel tipped with a subulate glume. — South Florida ( Garber, 

 Simpson ) . 



12. A. VirginicUS, L. (Broom Grass.) Culms 3° -4° high, narrowly 

 paniculate above the middle ; leaves linear, mostly glabrous, like th6 sheaths ; 

 spikes 2- 4, 9"- 12" long, loosely 6 -10-flowered, the very slender flexuous 

 rachis rather sparsely villous; glumes 1^" long, one third longer than the 

 joints, these naked below; sterile glume none; awns 6" -8" long. — In open 

 ground, everywhere. Sept. - Oct. — The most marked varieties are : 



Var. tetrastachyus, Hackel. Culms stouter ; leaves and sheaths villous 

 with spreading hairs ; spikes 4, 1'- Ij' long, 12-16-flowered. — Low ground, 

 Florida and Alabama. 



Var. Stenophyllus, Hackel. Culms slender, strictly erect ; branches 

 straight and erect or appressed ; leaves narrow-linear or filiform, erect ; spikes 



