FLOWERING PLANTS AND FERNS OF ARIZONA 481 



The prostrate stems, closely hugging the ground, make this a good 

 plant for control of erosion. This doubtless applies also to the 2 fol- 

 lowing species, which are very closely related to A. humistratus and 



perhaps only varietally distinct. 71 



25. Astragalus hosackiae Greene, Calif. Acad. Sci. Bui. 1: 157. 1885. 



Batidophaca hosackiae Rydb., North Amer. Fl. 24: 316. 1929. 



Navajo, Coconino, and Gila Counties, 5,500 to 7.000 feet, yellow 

 pine forests, July to September, type from Flagstaff {Busby in 1883). 

 Western New Mexico and Arizona. 



26. Astragalus sonorae A. Gray, PL Wright. 2: 44. 1853. 



Batidophaca sonorae Rydb., North Amer. Fl. 24: 317. 1929. 

 Batidophaca humivagans Rydb., ibid. p. 316. 



Apache County to Mohave County (Mt. Trumbull, Hualpai Moun- 

 tain), and Yavapai County, also in southern Arizona, 5.000 to 8.000 

 feet, mostly in pine forests, May to September, type of A. sonorae 

 from "between the San Pedro and the Sonoita" (Wright 1005), type of 

 B. humivagans from Mokiak Pass, northern Mohave County (Palmer 

 108). Southern Utah to Xew Mexico and Sonora. 



On the Kaibab Plateau (Buckskin Mountains), at about 8,500 feet 

 altitude, occurs a form with smaller leaflets and very few-flowered 

 racemes. This is var. tenerrimus (M. E. Jones) Kearney and Peebles 

 (A. humistratus var. tenerrimus M. E. Jones, Batidophaca tenerrima 

 Rydb.). 



27. Astragalus albulus Woot. and Standi., Contrib. U. S. Xatl. 



Herbarium 16: 136. 1913. 



Batidophaca albula Rydb., North Amer. Fl. 24: 317. 1929. 



St. Johns to Springerville. Apache County, 5.600 to 6.800 feet 

 (Marsh 14245, 14248), September. Western Xew Mexico and eastern 

 Arizona. 



*28. Astragalus accumbens Sheldon, Minn. Geol. and Nat. Hist. Sur- 

 vey Bot. Studies 1: 20. 1894. 



Batidophaca accumbens Rydb., North Amer. FL 24: 317. 1929. 



The writers have seen no Arizona specimens, but the species has 

 been collected at Fort Wirigate, New Mexico, about 30 miles east of 

 the Arizona State line. 



29. Astragalus gilensis Greene, Torrey Bot. Club Bui. 8: 97. 1881. 



Batidophaca gilensis Rydb., North Amer. Fl. 24: 318. 1929. 



Apache and Navajo Counties, 6,200 to 8,500 feet, gravelly slopes. 

 August. Western New Mexico and eastern Arizona. 

 The corolla is pink and white when fresh, drying blue. 



30. Astragalus sesquiflorus S. Wats., Amer. Acad. Arts and Sci. Proc. 



10: 346. 1875. 



Batidophaca sesquiflora Rydb., North Amer. FL 24: 318. 1929. 



Navajo County and northern Coconino County. 7.000 to 10.000 

 feet (in spruce-fir forests on Navajo Mountain). Southern Utah and 

 northern Arizona. 



See Jones, Marcus E. revision of the north American species of astragalus. 1^23 (p. 81). 



