54 POACEAE. 



39. AGROPYRON J. Gaertn. Wheat-grass. 



Annual or perennial grasses with flat or involute 

 leaves and terminal spikes. Spikelets 3-many-flowered, 

 sessile, single and alternate at each notch of the rachis, 

 the sides of the spikelet turned toward the rachis. The 

 lower glumes empty, narrower and usually shorter than 

 the flowering glumes, acute or awned; flowering glumes 

 rigid, rounded on the back, 5-7-nerved, usually acute or 

 awned at the apex. Palea 2-keeled, the keels often 

 ciliate. Stamens 3. Styles very short, distinct. Grain 

 pubescent at the apex, usually adherent to the palea. 



1. A. parishii Scribn. & Smith. Culms 5-10 dm. high, smooth, 

 retrorsely pubescent on the nodes; sheaths pubescent below, spar- 

 ingly ciliate on the margins, the lower shorter, the upper longer 

 than the internodes; leaves smooth below, scabrous above and on 

 the margins, the lower 1-2 dm. long, the uppermost 2.5-5 cm. long, 

 4-6 mm, wide at the somewhat constricted base, linear-attenuate; 

 spike composed of 8-12 compressed oblanceolate spikelets; spikelets 

 5-7-flowered, 16-20 mm. long, shorter than the internodes of the 

 rachis, these scabrous on the margins; empty glumes f as long as 

 the spikelet, nearly equal, linear, acute or acuminate, 5-nerved, 

 scarious on the margins; flowering glume lanceolate, acute, 9-11 

 mm. long, 5-nerved and scabrous above, minutely 3-toothed, awn- 

 less or awned; awn straight, slender, 6-8 mm. long; palea equaling 

 its glume, acute or obtuse. 



Occasional in the San Bernardino Mountains. First collected in 

 Waterman's Canyon by S. B. Parish. 



2. A. laeve (Scribn. & Smith.) Hitchc. Habit of the type, but 

 nodes and sheaths glabrous; awns equaling or exceeding the glumes 

 in length. 



Ballona Creek, near Mesmer; Santa Ana Mountains; San Ber- 

 nardino Mountains. First collected in the Cuyamaca Mountains 

 by Palmer. 



40. HORDEUM L. Barley-grass. 



Annual or perennial grasses, with flat leaves and ter- 

 minal cylindric spikes. Spikelets 1-flowered, usually in 

 3's at each joint of the rachis, the lateral generally short 

 stalked and imperfect; rachilla produced beyond the 

 flower. Empty glumes 2, all alike and subulate; flower- 

 ing glumes narrow lanceolate, rounded on the back, 

 rigid, persistent, obscurely 5-nerved above, usually 

 awned. Palea nearly equaling the glume, 2-keeled. 

 Stamens 3. Styles very short, distinct. Grain usually 

 adherent to the glume, hairy at summit. 

 Glumes not ciliate. 



