34 Agrostideae 



the spike; spike 2-4 cm. long, about 4 mm. wide; spikelets 2-3 

 mm. long ; empty glumes silky, obtuse ; flowering glumes gla- 

 brous, their margins united to near the middle ; awn about 4 mm. 

 long, slender. 



In low ground on the mesas near Inglewood. In a similar location near 

 San Diego. 



14. SPOBOBOIiUS R. Br. DROP-SEED GRASS. 



Perennial or annual grasses with flat or convolute 

 leaves and open or contracted panicles. Spikelets usu- 

 ally small, 1-flowered, sometimes 2-3-flowered. Glumes 

 in the 1-flowered spikelets 3, membranous ; the 2 outer 

 empty, the first somewhat the shorter ; the third equal- 

 ing or longer than the empty ones enclosing a perfect 

 flower and a 2-nerved palea. Stamens 2-3. Styles very 

 short, distinct. Grain free. 



1. S. airoides Torr. Perennial; culms erect, rather stout and 

 tufted, 4-9 dm. high; sheaths somewhat shorter than the inter- 

 nodes, the throat ciliate; ligule very short; leaves convolute, 

 tapering to a filiform apex, those of the culm 4-5, the upper 

 filiform, 2-3 cm. long ; panicle terminal, ovoid, often partly 

 included at the base, 2-3 dm. long, its branches again branching 

 and bearing scattered spikelets above the middle; spikelets light 

 lead-color or brown ; empty glumes obovate, nerveless, first 

 0.5-1 mm. long, second 1.5-2 mm. long; flowering glume con- 

 cave, broadly oval, 1-nerved, 2 mm. long ; palea broader than its 

 glume and a little shorter, truncate. 



Occasional in low ground. Wilmington; Westminster; San Bernardino; 

 San Diego. 



2. S. asperifolius (Nees.) Thurb. Culms branching, 2-4 dm. 

 high, ascending from stout creeping rootstalks, sheaths smooth, 

 loose, longer than the numerous short internodes, leaves flat, 

 scabrous, 3-8 cm. long, 2 mm. wide; panicle included at the base, 

 open, 9-18 cm. long, its branches scabrous, bearing single spike- 

 lets at the ends of very slender stiff branchlets ; spikelets tinged 

 with purple ; empty glumes lanceolate, 3-nerved, first 0.3-0.5 

 mm. long, second slightly longer; flowering glume oval, obtuse, 

 1-1.5 mm. long; palea equaling the glume. 



San Bernardino, Parish; Bear Valley, San Bernardino Mountains. 



