WOOTON AND STANDLEY FLOEA OF NEW MEXICO. 57 



Stems bulbous at the base or rliizomatous. 



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. jtlenum. 



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; 

 culms usually less than 1 me- 

 ter high 16a. P. bulbosum scia- 



pJiilum. 



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 Mexican! prope Guanaxuato 

 et Burras, in humidis, alt. 1,080 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 heUeri Nash, Bull. Torrey Club 26: 572. 1899. 

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

 Type locality: Ken-ville, 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. 

 Type locality: Pennsylvania. 



Range: Wasliington 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.) Beal, Grasses N. Amer. 2: 117. 1896. 

 Panicum reticulatum Torr. in Marcy, Expl. Red Riv. 299. 1852. 



Type locality: "Main fork of Red River," Texas. 



Range: Texas and Arizona to Mexico. 



New Mexico: Socorro (Plank 38). Di-y fields. 



5. Panicum arizonicum Scribn. & Merr. U. S. Dept. Agr. Div. Agrost. Circ. 32: 



2. 1901. 



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



Range: New Mexico and southern California to northern ^Mexico. 



New Mexico: Mogollon Creek; Mangas Springs; Burro Mountains; Hillsboro; mesa 

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

 Sonoran zones. 



6. Panicum dich.otomij0.orum Michx. Fl. Bor. Amer. 1: 48. 1803. 

 Type locality: "Hab. in occidentalibus montium Alleghanis." 



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

 Mexico, the West Indies, and South America. 

 New Mexico: Las Cruces {Planh 29). Lower and Upper Sonoran zones. 



