WOOTON AND STANDLEY— FLORA OF NEW MEXICO. 57 



Stems bulbous at the base or rhizomatous. 

 Glumes acuminate. 



Spikelets 3 to 5 mm. long; first glume 



acuminate to cuspidate 13. P. virgatum. 



Spikelets 6 to 8 mm. long; first glume 



acute 14. P. havardii. 



Glumes obtuse or merely acute, never acu- 

 minate. 



Culms from a rootstock, not bulbous 15. P. plenum. 



Culms from enlarged bulbous bases. 



Leaf blades over 5 mm. wide; culms 



usually over 1 meter high 16. P. bulbosum. 



Leaf blades less than 5 mm. wide; 

 cnlrns usually less than 1 me- 

 ter high IGa. P. bulbosum scia- 



philum. 



1. Panicum obtusum H. B. K. Nov. Gen. & Sp. 1: 98. 1816. 



Vine mesquite grass. 



Brachiaria obtusa Nash in Britton, Man. 77. 1901. 



Type locality: "Crescit in planitie montana regni Mexicani prope (iuanaxuato 

 et Burras, in humidis, alt. 1,0S0 hexap." 



Range: Colorado and Missouri to Texas, Arizona, and Mexico. 



New Mexico: Common from Gallup, Santa Fe, Las Vegas, and Clayton south- 

 ward across the State. Plains and river valleys, in the Lower and Upper Sonoran 

 zones. 



2. Panicum helleri Nash, Bull. Torrey Club 26: 572. 1899. 

 Panicum pernervosum Nash, Bull. Torrey Club 26: 576. 1899. 

 Type locality: Kerrville, Kerr County, Texas. 



Range: Missouri and Louisiana to Texas and New Mexico. 



New Mexico: West Fork of the Gila; Sierra Grande. Plains and low hills, in the 

 Upper Sonoran Zone. 



3. Panicum scribnerianum Nash, Bull. Torrey Club 22: 421. 1895. 

 Tyi>e locality: Pennsylvania. 



Range: Washington and Maine to California, New Mexico, Texas, and Maryland. 

 New Mexico: Las Vegas (Cockerell). Dry fields, in the Upper Sonoran Zone. 



4. Panicum fasciculatum reticulatum (Torr.) Boal, G ra ssd V. Amcr. 2: 117. 1896. 

 Panicum reticulatum Tarr. in Marry, Expl. Red Riv. 299. 1852. 



Type locality: "Main fork of Red River," Tex 



Range: Texas and Arizona to Mexico. 



New Mexico: Socorro (Plank 38). Diy fields-. 



5. Panicum arizonicum Scribn. A Merr. U. S. Dcpt. Agr. Div. Agrost. Circ. 32: 



2. 1901. 



Type locality: On mesas near Gamp Lowell, Santa Cruz Valley, Arizona. 



Range: New Mexico and southern California to northern Mexico. 



New Mexico: Mogollon ('rook; Mangas Springs; Burro Mountains; Billsboro; mesa 

 west of Organ Mountains. Dry hills and sandy mesas, in the Lower and Upper 

 Sonoran zones. 



6. Panicum dichotonuflorum Michx. Fl. Bor. Amer. 1:48. L803. 

 Type locality: "Hub. in octidentalibusmontium Alleghania." 



Range: Maine and Nebraska to Florida and Texas, and in California; also In 

 Mexico, the Wesl [ndies, and South America. 

 New Mexioo: Last ruces (Plant 29). Lower and Upper Sonoran a a. 



