286 POACE^. 



second glume 3 mm., floral glume 



2 mm. long 39 



u. Panicle usually narrow, 8-'i0 cm. 

 long, first glume 0.5-O.T mm., second 

 glume 1 mm., floral glume l.T mm. 

 long '11 



u. Panicle usually narrow, 12-20 cm. 

 long, first glume 0.5-1 mm., second 

 1.5 mm., floral glume 1.5 mm. long. 40 



u. Panicle usually narrow, 30-4.J cm. 

 long, first glume 1 mm., second 

 glume 1.5 mm. long 41 



1. S. Wolfii Vasey, Bull. Torr. Club, 10:62 (188:5). Vilfa 

 minima Vasey. 



A very slender and small annual, branching at the base, only 

 2-4 cm. high. Lower sheaths inflated; blades mostly radical, flat 

 or involute, 3-12 mm. long. Panicles spikelike, very simple, the 

 lateral ones partly enclosed by the sheaths. Eini)ty glumes oval. 

 subc(|ual, 0.7 mm. long; floral glume about 1 mm. long; palea as 

 long as its glume. 



'IMie plants seen were from the herbarium of Prof. Scribner, 

 No. T04, collected by J, Wolfe in 1873, on wet shores of Twin 

 Lakes, Colorado; also No. 1, 1077, J. Wolfe in the Gray herba- 

 rium. 



2. S. interruptus Vasey, Bull. Torr. Club, 15:8 (188G). S. 

 Arizonicits Thurb. of some collectors. 



A rather stout erect tufted pereimial, culm solid as in Maize, 

 about 40 cm. high. Sheaths longer than the internodes, throat 

 and back of the throat ciliate: ligule very short; blades of sterile 

 shoots scabrid above, flat or conduplicate, 10-15 cm. long, 2 mm. 

 wide, those of the culm 2-3 in number, the upper 3-5 cm. long. 

 Panicle terminal, barely exserted, interrupted, 10-18 cm. long, 1-2 

 cm. wide; rays mostly single, rather stout, erect. 3-5 cm. long, 

 flower-bearing along the upper half. Spikelets often crowded 

 toward the ends of the branches; empty glumes broadly lanceolate, 

 acute, 1-uerved, first 3-4 mm. long, second 5 mm. long; floral 



