48 



SPOROBOLUS PALMERI Scribn., sp.ii. (PI. V.) 



A deusely ca'spitose. ,i;laucous perennial, 3 to 5 dm. bigli, with narrow, spreading 

 leaves and diffuse panicles 20 to 30 cm. long. Sheaths smooth, striate, crowded 

 below, bearded at the throat. Ligule a short, dense fringe of hairs. Leaf-blades 

 5 to 10 or 12 cm. long, 2 to 4 mm. wide, rather rigid, very sharp-pointed, strongly 

 involute when dry and more or less ilexuous, smooth and glaucous, especially on 

 the upper surface the wliolc plant more or less glaucous. Panicle-branches 

 finely spreading, solitary, very smooth, pedicels spreading, somewhat flexuous, 

 primary branches rather rigid, spikelets about 3.5 mm. long. Outer glumes 



obtnse, the first about 2 mm. long, the 

 second 2.5 mm. long, the flowering 

 glume rather broad-ovate or ()l)loug, 

 obtuse, about 3.2 mm. long, a-nerved. 

 Palea with very broad margins, eiiual- 

 Ing or slightly exceeding tbe flow- 

 ering glume. 

 In alkali bottoms, growing in rather dense 

 bunches, near the city of Durango, 

 Mexico, altitude 1,850 meters (No. 180, 

 E. Palmer, June, 1896). The species 

 is named for the collector, Dr. Ed- 

 ward Palmer. 



SPOROBOLUS THURBERI Scribn., 

 sp. n. (Fig. 5.) Vilfajiliculmin'rhnvh. 

 in Bot. Mox. ]'>oundary Snrvey ined. 

 A slender, very mucli branched and leafy 

 perennial, 15 to 25 cm. high from 

 creeping rootstocks, with contracted, 

 linear, long exsertcd panicles 3 to 5 

 cm. long. Lower sheaths short and 

 crowded, the npper shorter than the 

 internodcs; ligule 1 mm. long, lacer- 

 ate. Leaf-blades 12 to Iti mm. long, 

 convolnte, setaceous, r i g id, a n d 

 widely sprciading or arcuate, mucro- 

 nate-pointed. Sl)ikelets straw- 

 colored, 1 to 5 mm. long. Empty 

 glumes broadly lanceolate, acute, 

 about one-third shorter than the 

 third or flowering glume, which is 

 pilose for half its length and niucro- 

 nate-pointed. I'alea \ ory acute, 

 strongly two-nerved, pilose on back, 

 e(inaling the flowering glume. 

 Camp 49, Plaza La iga, September 21, 1853, 

 Bigelow. Kolated to Sparoholns itliUs 

 but (|uite <lisfinct from that species, 

 especially in tlie characters of the 

 spikelets. 

 SPOROBOLUS SIMPLEX Scribn., sp. n. (Fig. 6.) 

 A low, densely ca'spitose, leafy annual, 5 to 15 cm. high with slender, .smooth culms, 



very sliort lower internodcs, flat leaves and linear panicles 2 to 4 cm. long. 



Lower sheaths loose, overlapping. Ligule hyaline, 2 to 3 mm. long, deeurrcDt. 



Leaf-blades 0.5 to 1.5 cm. long, 1 to 2 mm. broad, scabrous on the margins and on 



the nerves above, very rough near the rigid apex. Axis of panicle rather rigid, 





Fin. h.—Sporoholun thurhiri Siiiliii. : a, a', ciniity 

 glmiiea; h, lloiet, seen from tliebaek; c, llowciiiij; 

 Khime; d, palca. 



