32 POACEAE. 



1. Muhlenbergia capillaris (Lam.) Trin. Gram. Unifl. 191. 1824. 

 Stipa capillaris Lam. Tabl. Encyel. 1: 158. 1791. 



Culms 4.5-12 dm. tall, erect, simple, smooth or nearly so. Sheaths smooth, 

 the lower short and overlapping, the upper ones much longer; leaves 1.5-3 dm. 

 long, 2-4 mm. wide, scabrous; panicle 1.75-3 dm. in length or more, diffuse, 

 the capillary branches 1-2 dm. long, at length widely spreading; spikelets on 

 long hair-like pedicels which are clavate-thickened at the apex; outer scales 

 unequal, acute or short-awned, slightly scabrous; third scale, exclusive of the 

 awn, 4 mm. long, about twice as long as the first one, the awn 6-18 mm. long. 



Palmetto-lands, Andros and New Providence : Massachusetts to Missouri, Flor- 

 ida and Texas ; Cuba ; Porto Rico. LONG-AWXED HAIR-GRASS. PURPLE-GRASSS, 



21. SPOROBOLUS E. Br. Prodr. 169. 1810. 



Perennial or rarely annual grasses, with flat or convolute leaves and open 

 or contracted panicles. Spikelets generally small, 1-flowered, occasionally 2-3- 

 flowered. Scales in the 1-flowered spikelets 3, membranous; the 2 outer empty, 

 the first somewhat shorter; the third scale equalling or longer than the empty 

 ones; palet 2-nerved. Stamens 2-3. Styles very short, distinct. Stigmas plu- 

 mose. Grain free, and often early deciduous. [Greek, referring to the de- 

 ciduous grain.] About 100 species, in tropical and temperate regions, very 

 numerous in America. Type species: Agrostis indica L. 



Plants with no rootstocks ; culms tufted. 



Second scale one half as long as the spikelet or less. 



Panicle usually long and narrow, its branches spikelet-bearing to the base ; 



spikelets numerous. 



Second scale orbicular, rounded and erose-denticulate at the apex, one 

 fourth to one third as long as the spikelet ; spikelets loosely arranged 

 on long slender branches. 1. 8. indicus. 



Second scale ovate or oblong, acute or obtuse, about 

 one half as long as the spikelet ; spikelets densely 



arranged on the short and appressed branches. 2. 8. Bcrteroanus. 



Panicle loose and open, its branches naked at the base, 



spreading; spikelets few. 3. S. atrovircns. 



Second scale as long as the spikelet or nearly so. 



Spikelets about 1.5 mm. long; first scale about one fourth 

 as long as the second ; panicle branches rarely over 

 1.5 cm. long. 4. S. argutus. 



Spikelets about 2 mm. long ; first scale about one half 



as long as the second ; panicle branches longer. 5. S. domingensis. 



Plants with long stout rootstocks ; grass of sea beaches or 



saline situations. 6. S. virginicus. 



1. Sporobolus indicus (L.) E. Br. Prodr. 170. 1810. 



Agrostis indica L. Sp. PL 63. 1753. 



Agrostis tenacissima L. f. Suppl. 107. 1781. 



Sporobolus Jacquemontii Kunth, Eev. Gram. 2: 427, pi. 127. 1831. 



Glabrous. Culms 3-12 dm. tall, erect, tufted ; leaves 2-6 mm. wide, attenu- 

 ate into a long slender tip, the lower 2-3 dm. long, the uper shorter; pan- 

 icle 1-4 dm. in length, usually elongated, narrow, spike-like; spikelets 1.5-2 

 mm. long, the outer scales unequal, the second about one-third as long as the 

 third, obtuse, smooth and glabrous, the lower one shorter, and often erose- 

 truncate. 



Waste and cultivated grounds, New Providence and Eleuthera : West Indies ; 

 continental tropical America. Referred by Dolley to 8. tenacissimus Beauv. WEST 

 INPIAN RUSH-GRASS. 



