248 BOTANY. 



globe, ana most difficult to define by floral and carpological, but easily 

 recognized by the vegetative characters. 



Euphorbia (Poinsettia) cuphospekma, Boiss. I. c. 73 ; E. dentata, var. 

 cuphosperma, Engelm. Bot. Mex. Bound. 190. — A slender, erect annual, 1—1 £° 

 high, simple or with few erect branches, nearly glabrous, with few bristly 

 hairs ; leaves lance-linear, 1-2' long, upper involucral ones longer and a 

 little wider, but scarcely discolored at base, all entire or with a few teeth 

 on the revolute, scabrous margins ; the large involucres in loose clusters, 

 deeply campanulate, with 1 or 2, rarely more, slender, almost tubular glands ; 

 seeds short and thick, triangular, truncate at base, cross-ridged and tuber- 

 culate, with a minute caruncle. — Cienega (Creek), Arizona, near Tucson, 

 Rothrock, 1874 (577). 



A rare plant, found only once before, by Wright, mistaken by me for 

 a form of E. dentata, but well distinguished from that species (which extends 

 far into Mexico) by its involucres and seeds. E. dentata has much smaller 

 turbinate involucres, with broad glands, and smaller ovate or subglobose, 

 minutely tuberculated seeds. 



Euphorbia (Tithymalus) dictyosperma, Fisch. & Mey.; Boiss. I. c. 135; 

 Gray, Man. 434. — Camp Grant, Arizona, Rothrock (370), 1874. 



Euphorbia (Tithymaeus) campestris, Cham. & Schlecht, Linn. 

 1830, 84; Boiss. I. c. 146 ; E. esulaformis, Schauer, Linn. 1847, 729; Bot. 

 Mex. Bound. 192. — Several erect stems, 1-1^° high, from a stout perennial 

 root ; glabrous leaves linear-lanceolate ; lower branches sterile with nar- 

 rower leaves, upper ones flower-bearing ; terminal umbel 5-rayed ; exterior 

 floral leaves ovate-lanceolate, interior ones shorter, but all longer than wide; 

 involucres turbinate-campanulate, on pedicels of nearly their own length ; 

 glands semilunate, with short horns ; styles longer than the ovary, united 

 at base, bifid upward ; seeds ovate, gray, marked with irregular, shallow, 

 dark impressions. 



Willow Spring, Arizona, Rothrock, 1874 (213); and southward and 

 southwestward throughout Mexico. — The narrow leaves, especially on the 

 sterile branches, and the narrow floral leaves, distinguish this species from 

 its allies in the Southwest, and approach it, in habit at least, to the Euro- 

 pean E. Esida. 



