FLOWERING PLANTS AND FERNS OF ARIZONA J 45 



1. Panicum fasciculatum Swartz, Prodr. Veg. Ind. Ore. 22. 1788. 

 Pinal and Pima Counties, in open sandy ground and waste plai 



mostly around Tucson. Arkansas and Louisiana to Arizona, Mexico, 



and tropical America. 



This species typically has broad blades and open panicles with spike- 

 lets 2.1 to 2.5 mm. long. Only the var. reticulaturn (Torr.) Beal, with 

 narrow blades, narrow condensed panicles, and spikelets 2.6 to 3 mm. 

 long, is found in Arizona. 



2. Panicum arizonicum Scribn. and Merr., U. S. Dept. As:r., Div. 



Agrost. Cir. 32: 2. 1901. 

 Pinal, Cochise, Santa Cruz, and Pima Counties, 1,000 to 4,000 feet, 

 sandy ground and open rocky slopes, July to October, type from 

 Camp Lowell, Pima County (Pringle 465). Texas to southern Cali- 

 fornia and Mexico. 



3. Panicum texanum Buckl., Prelim. Kpt. Geol. and Agr. Survey Tex. 



App. 3. 1866. 

 Introduced at Wilmot, Pima County (Thornber 39, in 1903). Moist 

 open ground, Texas and northern Mexico, introduced in a few local- 

 ities eastward. 



4. Panicum dichotomiflorum Michx., Fl. Bor. Amer. 1: 48. 1803. 

 Tempe, Maricopa County (McLeUan and Stitt 576). Moist ground, 



a weed in waste places, Maine to Nebraska, south to Florida and 

 Texas, occasionally introduced westward. 



5. Panicum capillare L., Sp. PL 58. 1753. 



Apache, Navajo, Coconino, Yavapai, and Cochise Counties, 5,000 

 to 5.400 feet, moist open ground, July to October. Prince Edward 

 Island to British Columbia, south to Xew Jersey, Missouri, Texas, 

 Arizona, and California. 



Only var. occidentale Rydb. (P. barbipvlvinatum Nash) occurs in 

 Arizona, differing from the species in the shorter, less pubescent leaf 

 blades crowded toward the base, and more exserted panicles of some- 

 what larger spikelets. 



6. Panicum stramineum Hitchc. and Chase, Contrib. U. S. Xatl. 



Herbarium 15: 67. 1910. 

 Tucson (Pima County), and moist sandy plains near the Mexican 

 border, August to September. Southern Arizona and northwestern 

 Mexico. 



7. Panicum pampinosum Hitchc. and Chase, Contrib. U. S. Xatl. 



Herbarium 15: 66. 1910. 

 Pima County, at Wilmot {Thomber 193, the type collection), and 



Tucson Mountains (Griffiths 6939^). Xew Mexico, Arizona, and 

 Mexico. 



8. Panicum hirticaule Presl, Reliq. Haenk. 1: 308. 1830. 

 Mohave, Yavapai, Maricopa, Pinal. Cochis ( >, Santa Cruz, and Pima 



Counties, 1,000 to 4,000 feet, dry open ground and waste places, 

 June to September. Arkansas and western Texas to southern Califor- 

 nia, Mexico, and Colombia. 



