30 POACEAE. 



slender; panicle thinner; empty glumes 6-8 mm. long; flowering 

 glume 4 mm. long, nearly cylindric; awn 20-24 mm. long. Other- 

 wise like the type. 



Santa Monica Mountains, Hasse. 



11. MUHLENBERGIA Schreb. Drop-seed Grass. 



Perennial or annual grasses with convolute or flat 

 leaves and paniculate inflorescence. Rootstocks often 

 scaly. Spikelets 1-2-flowered. Glumes 3 or rarely 4; 

 the outer ones empty, membranous or hyaline, acute 

 and sometimes awned; the third 3-5-nerved, subtending 

 a palea and perfect flower, obtuse, acute or produced 

 into a capillary awn; stamens usually 3. Styles distinct. 

 Callus minute. Grain narrow, free, tightly enclosed in 

 the glume. 



1. M. parishii Vasey. Culms spreading, diffusely branched, 

 4-8 dm. high; panicles terminating the long, leafy, terminal and 

 lateral branches, 10-15 cm. long, its branches mostly alternate, the 

 lower distant and subspicate; spikelets sessile and crowded on the 

 branches; empty glumes membranous except the hispid green keel, 

 equal, lanceolate, acuminate, scarcely 4 mm. long, somewhat ex- 

 ceeding the flowering glume; flowering glume about 3 mm. long, 

 firm, scabrous, acute and terminating in a straight awn of about its 

 own length, sparingly villous at the base; palea about equaling the 

 glume, acute. {M. sylvatica californica Vasey.) 



San Bernardino Mountains, Parish; near Pasadena, Davidson; 

 San Diego. 



2. M. debilis Trin. Culms tufted, decumbent at base and 

 much branched, purplish throughout, 1-4 dm. high; leaves 25-50 

 mm. long, puberulent; ligule 1 mm. long, lacerate; panicle 5-12 cm. 

 long, usually spreading, branches 25-35 mm. long, mostly single, 

 sessile; spikelets 2-3 mm. long, short-pedicellate; empty glumes 

 nearly equal, j to ^ as long as the flowering glume, mostly obtuse 

 or eroded, hyaline; flowering glume slender, tapering', scabrous 

 throughout, terminated by a slender awn 25-35 mm. long; palea 

 about equal to the flowering glume. 



Common on dry ridges and exposed places in the chaparral belt. 

 Santa Monica, San Gabriel and Santa Ana Mountains, south to 

 San Diego. 



12. PHLEUM L. Timothy. 



Annual or perennial grasses with flat leaves and spike- 

 like inflorescence. Spikelets 1-flowered. Glumes 3, the 

 2 outer empty, membranous, compressed keeled, the 

 apex obliquely truncate, midnerve produced into an 

 awn, the third much shorter and broader, hyaline, trun- 

 cate denticulate at the apex. Palea narrow, hyaline. 



