GRASS FAMILY 137 



Loose sandy soil, deserts of northern Mexico, extending sparingly into the 

 adjoining U. S. Cargo Muchacho, Colorado Desert, Orcutt. 



Bef. BOUTELOUA ARENOSA Vasey, U. S. Dept. Agr. Div. Bot. Bull. 12 1 : 34. 1890. 



4. B. barbata Lag. Annual; culms spreading or prostrate, 6 to 12 inches 

 long ; spikes several, usually 4 to 6, about % to % inch long ; spikelets numer- 

 ous, imbricated; glumes unequal, scabrous on keel and somewhat so on back, 

 awn-pointed from a toothed apex, the second twice as long as the first, iy 2 

 lines long; lemma pilose below, 3-awned, the central between the obtuse sca- 

 brous lobes ; rudiment pilose at base, 2-lobed, 3-awned, enclosing an orbicular 

 scale; awns of spikelet about 1 line long. 



Deserts, Utah to southern California (The Needles, Jones 67a in 1884) and 

 south into Mexico. 



Eefs. BOUTELOUA BARBATA Lag. Var. Cienc. 2 4 : 141. 1805. B. polystachya Torr. U. S. 

 Eep. Expl. Miss. Paeif. 5:. 366. 1857; Thurb. in Wats. Bot. Cal. 2: 291. 1880. Chondrosium 

 polystachya Benth. Bot. Voy. Sulph. 56. 1844. 



5. B. rothrockii Vasey. Perennial; culms erect or spreading, 1 to 2 feet 

 high ; spikes several, usually 4 to 6, y<% to 1 inch long ; spikelets numerous, 

 imbricated; glumes unequal, scabrous on keel and back, cuspidate and 2- 

 toothed at apex, the second 1.14 lines long, about twice as long as the first; 

 lemma pilose below, 4-lobed, 3-awned, the awns equal, 114 lines long ; rudiment 

 pilose at base, consisting of 2 short truncate lobes, 3 equal awns about 1 line 

 long and an included orbicular scale. 



Mesas and foothills, Utah to southern California (Jamacha, Canby) and 

 Mexico. 



Eef. BOUTELOUA ROTHROCKII Vasey, Contr. Nat. Herb. 1: 268. 1893. 



6. B. radicosa Griff. Perennial ; culms 6 inches to 2 feet high, erect ; blades 

 mostly basal, flat; spikes several to many, % to 1 inch long, irregularly 1- 

 sided ; glumes somewhat unequal, rather broad, the second about 3 lines long ; 

 lemma smooth, bearing 3 short awns ; rudiment lanceolate, with 3 long awns. 



Upper foothills and mountains, southern California (Orcutt in 1884) and 

 New Mexico to Mexico. 



Eefs. BOUTELOUA RADICOSA Griff. Contr. Nat. Herb. 14: 411. 1912. Atheropogon radicosus 

 Fourn. Mex. PL 2: 140. 1886. Dinebra bromoides H.B.K. Nov. Gen. & Sp. 1: 172. 1816, not 

 Bouteloua bromoides Lag. 



7. B. gracilis Lag. Perennial; culms erect, 6 inches to l 1 /^ feet high; 

 sheaths and blades glabrous ; spikes 1 to 3, 1 to 2 inches long, usually a little 

 curved, the rachis not produced ; spikelets 2^/2 to 3 lines long, densely crowded, 

 pectinate ; glumes narrow, the first about % as long as the second, the latter 

 sparsely papillose-pilose on the keel ; lemma pilose, 3-cleft, the lateral divisions 

 awned, the terminal 2-toothed, awned between the teeth ; rudiment 3-awned, 

 pilose at base, a second rudimentary scale above. 



Plains and hills, mountains of southern California; extends from Manitoba 

 to Montana, south to Mexico. 



Locs. San Bernardino Mts., Abrams 2100, Parish Bros. 1528, Wilder 744; Santa Ana Canon, 

 Hall 7589; Jamacha, Canby in 1894. 



Refs. BOUTELOUA GRACILIS Lag.; Steud. Nom. Bot. ed. 2. 1: 219. 1840. Chondrosium 

 gracile H.B.K. Nov. Gen. & Sp. 1: 176. 1816. Bouteloua oligostachya Torr.; Gray, Man. ed. 

 2. 553. 1856; Thurb. in Wats. Bot. Cal. 2: 291. 1880. Atheropogon oligostachyum Nutt. Gen. 

 1: 78. 1818. 



8. B. hirsuta Lag. Perennial; culms erect, 8 inches to 1% feet high; 

 sheaths smooth; blades sparsely papillose-hairy, especially on the margins; 

 spikes 1 to 4, % to 2 inches long, the rachis produced into a prominent point 



