528 MISC. PUBLICATION 42 3, IT. S. DEPT. OF AGRICULTURE 



1. Ditaxis adenophora (A. Gray) Pax and Hoffman, Pflanzenreich 



IV. 147| 6 : 65. 1912. 



Argythamnia adenophora A. Gray, Amer. Acad. Arts and Sci- 

 Proc. 8: 294. 1870. 



Agua Caliente (western Maricopa County), mouth of Williams 

 River (Yuma-Mohave County). Western Arizona, southeastern 

 California, and Sonora. 



2. Ditaxis mercurialina (Nutt.) Coult., Torrey Bot. Club Mem. 5: 



213. 1894. 



Aphora mercurialina Nutt., Amer. Phil. Soc. Trans, ser. 2, 5: 

 174. 1837. 



Fort Apache (Navajo County). Kansas and Texas to eastern 

 Arizona. 



3. Ditaxis cyanophylla Woot. and Standi., Torrey Bot. Club Bui. 36: 



106. 1909. 



Slate Mountain, Flagstaff, and Walnut Canyon (Coconino County), 

 Coyote Spring near Springerville (Apache County), 5,900 to 6,500 feet, 

 pine forests. New Mexico to southern Nevada and northern Arizona. 



The flowers impart a purple color to water on boiling. 



4. Ditaxis brandegei (Millsp.) Rose and Stand]., Contrib. U. S. Natl. 



Herbarium 16: 13. 1912. 



Arqythamnia brandegei Millsp., Calif. Acad. Sci. Proc. ser. 2, 2: 

 220. 1889. 



Tule Tank and Gila Mountains (Yuma County) , dry slopes. South- 

 western Arizona to Sonora (?) and Baja California. 



The plant occurring in Arizona is var. intonsa Johnston. The plant 

 in Arizona attains a height of 1.8 m. The flowers impart a strong 

 purple color to water on boiling. 



5. Ditaxis lanceolata (Benth.) Pax and Hoffman, Pflanzenreich IV. 



147 6 : 71. 1912. 



Serophyton lanceolatum Benth., Bot. Voy Sulph. 42. 1844. 

 Argythamnia sericophylla A. Gray in S. Wats., Bot. Calif. 2: 



70. 1880. 



Southern Yavapai County to Pima and Yuma Counties, 1,400 to 

 2,300 feet, dry rocky slopes. Southwestern Arizona to southeastern 

 California, Sonora, and Baja California. 



Plants from excessively dry sites show a tendency to be either 

 wholly staminate or wholly pistillate. 



6. Ditaxis neomexicana (Muell. Arg.) Heller, Cat. North Amer. PL 5. 



1898. 



Argythamnia neomexicana Muell. Arg., Linnaea 34: 147. 1865. 



Greenlee County to Mohave, Maricopa, Pinal, Pima, and (proba- 

 bly) Yuma Counties, 1,000 to 3,400 feet. Texas to southern Arizona, 

 Sonora, and Baja California. 



Leaves lanceolate, acute, and serrulate or entire. 



