STANDLEY TREES AND SHRUBS OF MEXICO. 603 



21. Euphorbia tricolor Greenni. Proe. Amer. Acad. 33: 479. 1898. 

 Alclcma tricolor Millsp. Field Mus. Bot. 2: 417. 1916. 



Piiebla and Oaxaca ; type from Tehuaean, Piiebla. 



Slender shrub, 1 meter high or less, the branches puberulent at first ; leaves 

 slender-petiolate, oblong-ovate to ovate-orbicular, 1 to 2 cm. long, sparsely 

 pubescent beneath ; involucres in small terminal cymes, the appendages oblong- 

 ovate, entire or nearly so, white or purplish. 



22. Euphorbia leucocephala Lotsy, Bot. Gaz. 20: 350. pi. 2J,. 1895. 

 Chiapas. Guatemala and Honduras ; type from Cuilco, Guatemala. 



Shrub. 1 to 2 meters high ; leaves slender-petiolate, lance-oblong to oblong-oval, 

 3 to 6.5 cm. long, obtuse or rounded at apex, sparsely pubescent beneath ; in- 

 florescence terminal, large, of numerous cymes, the white bracts very conspicu- 

 ous ; appendages of the glands oblong-ovate. " Puno-puno," " flor de nino," 

 " flor de Pascua." (Chiapas). 



23. Euphorbia lucii-smithii Robins. & Greenm. Proc. Amer. Acad. 32: 36. 1896. 

 Michoacan to Chiapas ; type from Rancho de Calderon, Oaxaca. Guatemala. 

 Shrub, 3 to 4.5 meters high, the branches tomentulose ; leaves slender-petiolate, 



usually elliptic, 2 to 5 cm. long, obtuse or acute, pubescent beneath ; inflorescence 

 terminal, leafy, the bracts white, pink, or red ; appendages oblong or ovate, 

 white; capsule glabrous. 



Specimens from Chiapas are noteworthy because of their villous stems. 



24. Euphorbia cotinifolia L. Amoen. Acad. 3: 112. 1756. 

 Alcctoroctonum cotinifoliuin Scblecht. Linnaea 19: 252. 1845. 

 Alectoroctonutn scotanum Schlecht. I.innaea 19: 252. 1845. 

 Alectoroctonum yavalquahuitl Schlecht. Linnaea 19: 252. 1845. 

 EitpJiorMa scotana Boiss. in DC. Prodr. 15^:60. 1865. 

 Aldema cotinifolia Millsp. Field Mus. Bot. 2: 416. 1916. 



Oaxaca and Veracruz. Central America and northern South America ; type 

 from Curasao. 



Shrub or tree, 3 to 6 meters high ; leaves long-petioled, rounded-ovate or 

 orbicular, 5 to 14 cm. long, glabrous beneath or sparsely pubescent ; involucres 

 in dense terminal cymes ; appendages of the glands broader than long, crenate. 

 " Trompillo," " pinoncillo," " raala-mujer " (Oaxaca); " mata-gallina " (Vera- 

 cruz); "barrabas" (Costa Rica); " sapo " (Nicaragua); " hierba mala" 

 (Guatemala); " lechera " (Venezuela); " manzauillo " (Colombia). 



The milky sap has violent emetic-cathartic properties, and in doses of even 

 small quantity is poisonous. It has been employed by some of the Indians of 

 Central America for criminnl poisoning. The natives of certain parts of South 

 America are said to make use of it as an arrow poison and for poisoning fish. 

 The juice is sometimes used to cauterize ulcers. The seeds also are said to have 

 drastic purgative properties. 



25. Euphorbia xanti Engelm. ; Boiss. in DC. Prodr. 15': 62. 1865. 

 Euphorbia gymnoclada Engelm. Proc. Amer. Acad. 5: 171. 1861. Not E. gym- 



noclada Boiss. 1860. 



Aldema xanti Millsp. Field Mus. Bot. 2: 417. 1916. 



Baja California ; type from Cabo de San Lucas. 



Shrub, 1 to 3 meters high, with glabrous branches; leaves petiolate, linear- 

 lanceolate to elliptic or broadly obovate, glabrous or nearly so ; involucres few, 

 axillary or in terminal cymes ; appendages white or pink, rounded-obovate. 

 " Liga." 



The leaves are remarkably variable in form, and it may be that the material 

 represents two species ; but the involucre characters are uniform. The milky 



