OF ARTS AND SCIENCES. 7,", 



Euphorbia serpyllifolia, Pers. On gravelly ridges near Guav- 

 mas. (187.) 



Euphorbia setiloba, Engelm. Near the bea;h, Los Angeles 

 Bay. (629.) — About Guaymas. (185, 1851 634.) The latter a 

 more open form with longer internodes and larger leaves, and the 

 appendages less deeply 3-4-lobed. 



Euphorbia petrina. Near E. setiloba ; annual, prostrate, much 

 branched and slender, more or less densely pubescent throughout with 

 short spreading hairs: leaves very shortly petiolate, entire, obliquely 

 ovate or oblong-ovate, obtuse, somewhat cordate at base, 3 lines long 

 or usually much less: involucres solitary in the axils, shortly' pedun- 

 culate, minute, turbinate-campanulate ; glands greenish, reniform, un- 

 appendaged : capsule (and pedicel) pubescent, \ line long : seeds 

 oblong-ovate, quadrangular, strongly and irregularly 3-4-rugose or 

 -pitted. — Common among rocks at summit of San Pedro Martin 

 Island. (412.) 



Euphorbia portulana. Of the same group ; annual, prostrate, 

 much branched and slender, the minute and sparse pubescence spread- 

 ing : leaves oblong to broadly elliptical, obtuse at both ends, entire, 

 petiolate, 4 lines long or less: involucres oblong, f- line long, nearly 

 glabrous, somewhat contracted above ; lobes subulate, slightly ciliate ; 

 glands dark purple, the appendages variable in form, often unequal 

 (1 or 2 larger), entire or nearly so, white or pinkish: stamens very 

 few : ovary villous ; styles bifid nearly to the middle : capsule sub- 

 acutely lobed, nearly a line long : seed oblong, tetragonal, very strongly 

 4-5-rugose. — Island in Guaymas harbor. (321.) 



Euphorbia gi.yptosperma, Engelm. High gravelly ridges at 

 Guaymas. (187, in part.) 



Euphorbia polycarpa, Benth. Several forms, belonging chiefly 

 to the variety with scarcely appendiculate glands {E. micromera, 

 Boiss.). By garden fences at Guaymas and on islands in the harbor 

 (96, 324, 335), and at Los Angeles Bay on sandy bottoms, sometimes 

 covering many yards of surface (632, 633). — Also var. hirtella, 

 Boiss., in like localities at Los Angeles Bay. (630.) 



Euphorbia Florida, Engelm. In rocky places high in the moun- 

 tains above Guaymas. (20'J.) 



Euphorbia maculata, Linn., or near it; the glands unappendaged 

 and capsules glabrous. Abundant in low sandy places about Guaymas. 

 (186.) 



Euphorbia pediculifera, Engelm. Stony ridges near I 



Angeles Bay. (631.) 



