376 



EUPHORBIACEAE. 



[Vot. II. 



16. Euphorbia marginata Pursh. White-margined Spurge. (Fig. 2322.) 



Euphorbia marginata Pursb, Fl. Am. Sept. 607. 

 1814. 



Annual, bright green, glabrous or pubescent. 

 Stem rather stout, erect, ic/-$ tall, somewhat 

 channelled, usually pilose, topped by a mostly 

 3-rayed umbel; leaves except the whorl subtend- 

 ing the umbel, scattered, ovate to obovate, fo"- 

 $%' long, entire, sessile, rays of the umbel 

 forked; bracts large, white-margined; involu- 

 cres campanulate, often clustered, 2" long, 

 usually pubescent, bearing 3 glands subtended 

 by white renifonn appendages; capsule de- 

 pressed-globose, 3" in diameter, usually pubes- 

 cent, the lobes rounded; seeds ovoid-globose, 

 terete, about 2" long, dark ash-colored, reticu- 

 late-tuberculate. 



In dry soil, Minnesota to Colorado, south to 

 Texas. Introduced into waste places in the Central 

 and Atlantic States. May-Oct. 



17. Euphorbia cuphosperma (Kngelm.) 

 Boiss. Warty Spurge. (Fig. 2323.) 



Euphorbia dentata var. cuphosperma Kngelm. Bot. 



Mex. Bound. Surv. 190. 1859. 

 Euphorbia cuphosperma Boiss. in DC. Prodr. 15: Part 



a, 73. 1862. 



Annual, usually sparingly pubescent. Stem erect, 

 slender, simple, or sparingly branched, 8'-i$' high. 

 Leaves opposite or alternate, linear, oblong, or 

 linear-lanceolate, io"-3' long, entire, undulate, or 

 denticulate, narrowed into a slender petiole; in- 

 volucres crowded at the ends of the branches, nearly 

 sessile, glabrous, or nearly so, nearly 2" long, bear- 

 ing about 4 long-stalked unappendaged glands; 

 capsule glabrous, or sparingly pubescent, 2%" in 

 diameter, seeds narrowly ovoid, about I >" long, ir- 

 regularly 4-angled, ridged and slightly tuberculate. 



South Dakota to Colorado and Mexico. Aug. -Sept. 



18. Euphorbia dentata Michx. 

 Toothed Spurge. (Fig. 2324.) 



Euphorbia dentata Michx. Fl. Bor. Am. 2: 211. 



1803. 



Annual, dull green, pubescent. Stem erect 

 or ascending, 8'-i5' high, somewhat woody 

 below, branched, the branches mostly ascending; 

 leaves opposite, or the lowest alternate, varying 

 from ovate to nearly linear or orbicular-oblong, 

 *>"-$%' long, coarsely dentate, narrowed into 

 slender petioles, the nerves prominent beneath ; 

 involucres clustered at the ends of the branches, 

 oblong-campanulate, about \}/ 2 " long, 3-5-lobed, 

 bearing 1-4 yellowish short-stalked glands with- 

 out appendages; capsule glabrous, 2 // -2^ // in 

 diameter; seeds ovoid or ovoid-globose, ash- 

 colored, irregularly tuberculate, inconspicuously 

 4-angled. 



In dry or moist soil, Pennsylvania to South 

 Dakota, Louisiana and Mexico. July-Oct. 



