18. A. Floridanus Scribii. incd. 



Culms sul)teret(>, braucliiiig inuoh near the top, 90-120 cm. 

 liigli. Upper sheaths slightly inflated, those of the extreme apex 

 narrow and extending to the base of the spikes. Spikes in pairs, 

 sessile, zigzag, 3-4 cm. long; lateral pedicels a little shorter and 

 stouter than those of A. Vinjinirus. The whole plant is sonie- 

 vvliat intermediate between A. Virr/iiiicus and A. macrouriis, with 

 which this has been somewhat hastily compared. Low pine land. 



Florida, G. T. X(us/i, 1572, lOSl, in 18!t4. 



10. A. Leibmanni Hack. Flora 132 (1885). A. macrothrix, 

 Fourn. Mex. PI. Fnuui. dram. 00 (188G). 



Culms branching sjiariiigly above, 15-20 cm. high. Leaf- 

 blades smooth, with a few soft hairs, 2-5 cm. long. 2-3 mm. wide. 

 Spikes exserted or enclosed, 3-4 together, simple or branching, 2-3 

 cm. long, hairs of the rachis and pedicels exceeding tlie spikelets. 

 The 2 outer glumes of the sessile s^nkelet nKMubrajious, ovate-acute, 

 3 mm. long, first 2-keeled, 2-ncrved, second 1-keeled. third and 

 fourth hyaline and shorter, the awn of the latter 15 cm. long. 

 Stamen 1. Sterile spikelets 2 mm. long on pedicels 3 mm, long of 

 one to two glumes. 



Mexico, Bo/irr/cfiK 2370, Palmer 227 ; Texas, XcdUcij, sent out 

 by him as A. niarronnis Miclix. var. pionilus Vasey. 



Var. Mohrii Hack. D. C. Monog. Phan. G : 413 (188D). 



Plant (es])ecially the sheaths) elotlied with numerous soft hairs. 

 Culm 90-120 cm. high, with many branches above. The lower 

 blades GO cm. long, 5 mm. wide, the upper becoming mere 

 sheaths partially enclosing 3 or more slender spikes. Pedicels 4 

 mm. long. Sessile sjiikelets 4 mm. long, awn 2 cm. long. 



Alabama, Mohr. 



20. A. longiberbis ITacK. i^lora 08 : 131 (1885). //. fpfra- 

 sfar/ti/us, var. disfacJn/ns Chapm. Fl. S. States, 581 (1800). 

 A tufted perennial, sparingly branched above, GO-80 em. high. 

 Sheaths silky hairy, those on the middle of the culm half as long 

 as the internodes; blades flat, smooth, or with a few silky hairs 

 below, 2-4 mm. wide. Spikes mostly in pairs, about 3 cm. long, at 

 length protruding from the sheath, which is 3.5-5 cm. long; apex 



