POACEAE. 57 



The more common form in open pine forests, and ranging north- 

 ward to northern California. 



42. SITANION Rafin. 



Csespitose perennials, with usually flat leaves and 

 bearded spikes. Spikelets usually 2 (1-3) at each joint 

 of the articulate rachis of the spike, 2-several-flowered. 

 Empty glumes 2 or sometimes 3, many-parted from near 

 the base or bifid or subulate and entire, awned; flower- 

 ing glumes terminating in a single awn or trifid or 3- 

 awned. Palea as long as its glume, entire, bidentate 

 or 2-awned. Stamens 3 Styles short. Grain adherent 

 to its glume and palea, hairy at the summit. 



Empty glumes deeply cleft into 3-11 or more 



setaceous awns. 1, S. jubatum. 



Empty glumes bifid above the middle or all entire 

 and subulate or setaceous. 

 Glumes 2-nerved. 2. S. californicum. 



Glumes or some of them 3-nerved. 3. S. hanseni. 



1. S. jubatum J. G. Smith. Culms erect, 6-9 dm. high, smooth; 

 lower sheaths hirsute, the upper minutely pubescent or sparsely 

 hirsute, becoming smooth; ligule 1 mm. long; leaves 10-18 cm. long, 

 3-5 mm. wide, strigose-pubescent throughout and sparsely hirsute 

 above, midnerve prominent beneath; spike 1-2 dm. long, densely 

 flowered; empty glumes 4, 3-many-parted from about the middle, 

 the lobes setaceous, mostly 8-10 cm. long; spikelets 2-4-flowered, 

 the second hermaphrodite, the other sterile or the upper staminate; 

 flowering glume linear-lanceolate, 8-10 mm. long, smooth below, 

 sparsely scabrous above, 5-nerved, trifid at the apex, lateral lobes 

 setaceous, the middle prolonged into a slender scabrous awn, 8-12 

 cm. long; internodes of the rachis 5-7 mm. long, glabrous. (5. 

 muUisetum J. G. Smith.) 



Rather common on mesas and grassy hills. March-May. 



2. S. californicum J. G. Smith. Culms tufted, ascending, 1.5-2.5 

 dm. high, rather densely pubescent above; lower sheaths densely hir- 

 sute, the upper minutely puberulent; ligule obsolete; leaves 2-8 cm. 

 long, 3-4 mm. wide, scabrous above and on the margins, densely pu- 

 berulent on the back; spike rather loosely flowered, 5-8 cm. long; 

 lowest flower of one or both spikelets sterile; empty glumes 4, entire, 

 3-5 cm. long; flowering glume Hnear, 10-12 mm. long, finely scabrous, 

 awn stout, about 4 cm. long; palea 2 mm. shorter than its glume, 

 scabrous on the nerves below; internodes of the rachis 4-5 mm. 

 long, scabrous throughout. 



Rather common in open pine woods in the San Gabriel and San 

 Bernardino Mountains. June-August. Another closely related 

 species, S. glabriwi J. G. Smith, is frequent in the San Jacinto and 

 Cuyamaca Mountains. It is readily distinguished by the glabrous 

 culms and sheaths. 



