POACEAE 125 



involute on the margins and at the summit : panicle 2.5-8 cm. hjng, 4-10 mm. wide, dense 

 and spike-like : spikelets 2-2.5 mm. long. 



On sandy shores, Virginia to Florida and Texas. Also in tropical America. Summer and fall. 



60. EPICAMPES Presl. 



Tall perennial grasses, with usually stout stems, flat leaf-blades, and contracted dense 

 panicles. Spikelets 1-flowered ; empty scales about equal, very nearly as long as to some- 

 what exceeding the thinner flowering scale which is frequently awned, the awn inserted 

 just below the apex. Stamens 3. Styles distinct, short. Stigmas plumose. 



1. Epicampes ligulata Scribn. Stems 8-12 dm. tall, stout : ligule pronounced, 1-2 

 cm. long ; blades 5 dm. long or less, 3-5 mm. wide, usually folded : panicle 2.5-4 dm. 

 long, 1.5-3 cm. wide : spikelets about 2.5 mm. long. 



In dry soil, central Texas to Arizona. Also in Mexico. Summer and fall. 



61. POLYPOGON Desf. 



Annual or perennial grasses, with usually decumbent or rarely erect stems, flat leaf- 

 blades, and terminal panicles, generally very dense, which are cylindric and spike-like, or 

 sometimes broader and more lax. Spikelets articulated below the empty scales, crowded, 

 1-flowered. Scales 3, the 2 outer empty, about equal in length, each terminating in an 

 erect slender awn, the third scale smaller, thinner, often hyaline, enclosing a smaller palet 

 and a perfect flower, entire, emarginate, or 2-toothed, awned or awn-])ointed, when entire 

 the awn terminal, otherwise dor.sal, the awn slender, either long with a twisted base and 

 geniculate at the middle, or short and erect, sometimes reduced to a mere point. Stamens 

 1-3. Styles short, distinct. Stigmas plumose. Beard Grass. 

 Panicle silky : awn of the empty scales of the spikelet 2-3 times as long as the 



scale. 1. -P. Monspeliensig. 



Panicle dull, often interrupted : awn of the empty scales of the spikelet about as 



long as the scale. 2. P. littoralis. 



1. Polypogon Monspeli6nsis ( L. ) Desf. Stems 6 dm. tall or less, erect, from a 



usually decum])ent base : leaf-ltlades 4-15 cm. long, 3-6 mm. wide, rough : panicle 2-10 



cm. long, dense and spike-like : spikelets crowded, the empty scales about 2 mm. long, 



obtuse, slightly bifid, rough, bearing a bent awn 4-6 mm. long, the flowering scale muc'h 



shorter, erose-truncate, hyaline, bearing a delicate awn about 0.5 mm. long, inserted below 



the apex. 



In waste places, New Hampshire to South Carolina, and very common in western North America 

 from British Columbia to Mexico. Naturalized from Europe. Summer and fall. 



2. Polypogon littoralis Sm. Stems tufted, 1.5-9 dm. tall, erect: leaf-blades erect, 

 1.5 dm. long or less, 3-8 mm. wide: panicle 3-15 cm. long, 6-40 mm. wide: spikelets, 

 exclusive of the awns, about 2 mm. long. 



In wet places, Louisiana ; and from British Columbia to California. Naturalized from the Old 

 World. Summer. 



62. CINNA L. 



Tall perennial grasses, with flat leaf-blades and long terminal contracted or open pan- 

 icles, often nodding, its branches slender and usually drooping. Spikelets numerous, flat- 

 tened, 1-flowered, the rachilla articulated below the empty scales. Scales 3, the 2 outer 

 empty, persistent, keeled, acute, the third one similar in texture, stalked, bearing just 

 below the somewhat obtuse apex a short awn or awn-like point, the scale enclosing a 

 slightly smaller 1-nerved keeled palet, the keel minutely ciliate, and a perfect flower. 

 Stamen 1. Styles short, distinct. Stigmas plumose. Reed Grass. 

 Panicle contracted at maturity, its filiform branches erect, often drooping : spike- 

 lets 4-,') mm. long, the first scale much shorter than the second. 1. c. arundinacea. 

 Panicle open, its capillary branches flexuous and drooping : spikelets 3 mm. long, 



the first scale about equalling the second. 2. C. Mifolia. 



1. Cinna arundinacea L. Stems 6-15 dm. tall : leaf-blades 1.5-3 dm. long, 4-14 



mm. wide, rough : panicle 1.5-3 dm. long, usually contracted, sometimes purple : scales 



of the spikelet acute, rough, the flowering scale slightly exceeded or equalled by the second, 



usually bearing an awn about 0.5 mm. long from the 2-toothed apex. 



In moist woods and swamps, Newfoundland to the Northwest Territory, North Carolina, Louisiana, 

 Missouri and Texas. Summer and fall. 



2. Cinna latifolia (Trev. ) Griseb. Stems 6-1 2 dm. tall : leaf-blades 1-2.5 dm. long, 

 4-12 mm. wide, rough : panicle 1-2.5 dm. long, the capillary branches generally spreading 



