FLOWERING PLANTS AND FERNS OF ARIZONA 457 



2. Dalea amoena S. Wats., Amer. Nat. 7: 300. 1873. 



Psorodendron amoenum Rydb., North Amer. Fl. 24: 44. 1919. 



Coconino and Mohave Counties, 500 to 4,700 feet, occasional, 

 April and May, type from northern Arizona. Southern Utah and 

 and Nevada, northern Arizona. 



In D. amoena, which is known from only a few collections, the hairs 

 of the calyx are short and closely appressed. The var. pvbescens 

 (Parish) Peebles (Parosela johnsoni var. pubescens Parish, Psoroden- 

 dron pvbescens Rydb.), occurs in the vicinity of Lees Ferry, Coconino 

 County. It is distinguished by spreading, usually longer hairs on 

 the calyx. 



3. Dalea schottii Ton*., U. S. and Mex. Bound. Bot. 53. 1859. 



Psorodendron schottii Rydb., North Amer. Fl. 24: 44. 1919. 



Southwestern Yuma County, infrequent, type from the same local- 

 ity. Southwestern Arizona, southern California, and Baja California. 



4. Dalea spinosa A. Gray, Amer. Acad. Arts and Sci. Mem. ser. 2, 5: 



315. 1855. 



Psorodendron spinosum Rydb., North Amer. Fl. 24: 45. 1919. 



^Yestern Mohave, Yuma, western Maricopa, and western Pima 

 Counties, below 1,000 feet, in sandy washes, April and May, type 

 from Yuma County. Arizona, southern California, Baja California, 

 and Sonora. 



Smoketree. 



*5. Dalea polyadenia Torr. ex S. Wats, in King, Geol. Expl. 40th 

 Par. 5: 64. 1871. 



Psorothamnus polyadenitis Rvdb., North Amer. Fl. 24: 46. 

 1919. 



Not known from Arizona but collected not far from the northern 

 boundary in southern Utah (at St. George, Siler in 1875). South- 

 western Utah to the Mohave Desert, California. 



6. Dalea emoryi A. Gray, Amer. Acad. Arts and Sci. Mem. ser. 2, 5: 



315. 1855. 



Psorothamnus emoryi Rydb., North Amer. Fl. 24: 47. 1919. 



Abundant on sandy mesas near Yuma (Yuma County), the type 

 locality, below 500 feet, flowering in spring (occasionally in autumn). 

 Southern California, Baja California, Arizona, and Sonora. 



Host of the rare parasitic plant Pilostyles thurberi. 



7. Dalea scoparia A. Grav, Amer. Acad. Arts and Sci. Mem. ser. 2, 



4: 32. 1849. ~—*~mm— 



Psorothamnus scoparius Rydb., North Amer. Fl. 24: 48. 1919. 



WHlcox Flat, Cochise County {Shrere 4256), near Leupp, eastern 

 Coconino County (Whiting 3321). New Mexico, southeastern Ari- 

 zona, Chihuahua, and Coahuila. 



