24 POACEAE. 



crowded, 2.5 mm. long; scales l-nerved, acute. — M. Eather rare, in waste 

 places. Nat. of Eu. — Sum. 



21. PHLEUM L. Annual or perennial grasses, with flat leaf-blades and 

 terminal, often long-pedunculate, dense spike-like panicles, which are from 

 elongate, narrow and cylindric, to short, oblong or nearly ovoid. Spikelets 

 crowded, 1-flowered, compressed. Scales 3, the 2 outer empty, persistent, mem- 

 branous, compressed-keeled, obliquely truncate at the summit, awned, the third 

 scale much shorter, hyaline, truncate and denticulate at the apex, enclosing a 

 narrow palet of similar texture and a perfect flower. Stamens 3. Styles dis- 

 tinct, rather long. Stigmas plumose. 



1. P. pratense L. Stems 3-12 dm. tall: leaf -blades 7-23 cm. long, 4-6 mm. 

 wide: spike cylindric, 3-18 cm. long, 5-8 mm. in diameter: empty scales of the 

 spikelet, exclusive of the awn, 2.5 mm. long, the awn less than i their length. — 

 Common, in fields and on roadsides. — Sum. — Timothy. 



22. ALOPECinitrS L. Annual or perennial grasses, erect, or decumbent 

 at the base, with flat and lax or rather rigid or convolute leaf -blades, and dense 

 terminal spike-like cylindric panicles. Spikelets articulated below the empty 

 scales, readily deciduous, l-flowered, compressed, crowded. Scales 3, the 2 

 outer empty, acute, sometimes short-awned, usually more or less united at the 

 base, compressed-keeled, the keel ciliolate or somewhat winged, the third scale 

 broad, hyaline, obtuse, bearing a short awn or point on the back, the margins 

 sometimes united into a short tube at the base, enclosing a perfect flower and 

 sometimes also a hyaline keeled palet. Stamens 3. Styles distinct, or rarely 

 more or less united at the base. Stigmas elongate, somewhat plumose with 

 short hairs. 



1. A. myosuroides Huds. Stems 3-6 dm. tall: leaf -blades 4-18 cm. long, 2-6 

 mm. wide: spike 4-10 cm. long, 4—8 mm. in diameter: empty scales of the 

 spikelet narrowly winged, 4-5 mm. long, the flowering scale equalling or slightly 

 exceeding the empty ones, the awn inserted near the base and about twice its 

 length, bent. — S. Rare, in fields near Pleasant Grove. Nat. of Eu. — Sum. 

 — Foxtail. 



23. SPOROBOLUS R. Br. Perennial or rarely annual grasses, varying 

 much in habit, with flat or convolute leaf-blades and terminal panicles, which 

 are contracted, sometimes cylindric and spike-like, often elongate, or open and 

 diffuse. Spikelets small, sometimes minute, 1-flowered, or very rarely 2-4- 

 flowered. « Scales 3, rarely 4-6, membranous, acute or obtuse, rarely awn- 

 pointed or short-awned, the 2 outer empty, the flrst shorter than the second, 

 the remaining scale or scales longer or about equalling the second scale, enclos- 

 ing a perfect flower, and a 2-nerved, often deeply 2-cleft or 2-parted, palet 

 which is equal in length to, or a little shorter than, the scale, rarely awned and 

 exceeding it. Stamens 2 or 3. Styles short, distinct. Stigmas plumose. — Sum. 

 and fall. — Rush-grass. Dropseed. 



Upper leaf-sheaths enclosing panicles which are usually concealed or sometimes 

 partially protruding : terminal panicle contracted, narrow. 1. 8. clandestinus. 



Flowering scale appressed-pubescent below with long hairs. 



Flowering scale glabrous. 2. S. asper. 



Upper leaf-sheaths not enclosing panicles. 3. 8. heterolepis. 



1. S. clandestinus (Spreng.) A. Hitehc. Stenia 6-12 dm. tall: leaf -blades 7-35 

 cm. long, 2-4 mm. wide, attenuate into a long slender involute tip: panicle 5-13 



