FLOWERING PLANTS AND FERNS OF ARIZONA 543 



23. Euphorbia capitellata Engelm. in Ton*., U. S. and Mex. Bound. 



Bot. 188. 1859. 

 Euphorbia pycnanthema Engelm., ibid. 



Euphorbia rusbyi Greene, Calif. Acad. Sci. Bui. 2: 57. 1886. 

 Chamaesyce capitellata Miilsp., Field Museum Nat. Hist. Bot. 



Ser. 2: 408. 1916. 

 Chamaesyce pycnanthema Miilsp.. ibid. p. 411. 

 Chamaesyce rusbyi Miilsp., ibid. 

 Throughout the State except the lower western desert and north- 

 eastern portion, 1.500 to 5,000 feet, type of E. capitellata from San 

 Bernardino. Cochise County {Wright in 1851), type of E. rusbyi from 

 northern Arizona (Busby in 1883; . Western Texas to Arizona and 

 northern Mexico. 



24. Euphorbia hirta L., Sp. PL 454. 1753. 



Euphorbia pUulifera L.. var. discolor Engelm. in Torr., U. S. 



and Mex. Bound. Bot. 188. 1859. 

 Euphorbia pUulufera L.. sensu many authors. 

 Chamaesyce hirta (L.) Miilsp.. Field Museum Nat. Hist. Bot. 

 Ser. 2: 303. 1909. 

 Cochise, Santa Cruz, and Pima Counties. 3.200 to 4,900 feet. 

 Florida, Texas, and southern Arizona, southward to Argentina. 



25. Euphorbia hyssopifolia L., Syst. Nat. ed. 10, 2: 1048. 1759. 



Euphorbia jonesii Miilsp., Pittonia 2: 89. 1890. 



Chamaesyce hyssopifolia Small, N. Y. Bot. Gard. Bui. 3: 429. 



1905. 

 Chamaesyce jonesii Miilsp., Field Museum Nat. Hist. Bot. 



Ser. 2: 410. 1916. 



Yavapai, Graham. Gila, and eastern Maricopa Counties, where 

 infrequent. Santa Cruz. Cochise, and eastern Pima Counties, where 

 common, 1.200 to 6.000 feet, type of E. jonesii from Bowie. Cochise 

 County {Jones 4247). Southern Florida, western Texas to Arizona, 

 south to South America, 



26. Euphorbia vermiculata Raf., Amer. Month. Mag. 2: 119. 1817, 



and op. cit. 206. 1818. 



Chamaesyce vermiculata House. N. Y. State Museum Bui. 

 233-234: 8. 1922. 



Mountains of Apache. Navajo, Gila, and Cochise Counties, about 

 6.000 feet. Nova Scotia to Pennsylvania and west to Michigan, 

 probably introduced in British Columbia, Xew Mexico, and Arizona, 



Chamaesyce rothrockii Miilsp.. type from Crittenden, Santa Cruz 

 County {Rothrock 672), is intermediate between E. vermiculata and 

 E. maculata L., as are some of the collections included above. No true 

 E. maculata has been seen from Arizona, 



27. Euphorbia albomarginata Torr. and Gray, U. S. Rpt. Expl. Miss. 



Pacif. 2-': 174. 1855. 



Chamaesyce albomarginata Small. Fl. Southeast. U. S. 710, 1333. 



1903. 



Throughout the State except the extreme northern, northeastern, 



and southwestern portions, 1.000 to 6,000 feet, often common on 



clay and loam flats. Oklahoma to California and northern Mexico. 



744*— 42 35 



