EUPHORBIA, SECTION TITHYMALUS. 103 
mm. high; cocci flat or rotund; styles free, spreading, 
less than 1 mm. long, divided to the middle or less, the tips 
slender; stigmas clavate capitate; seeds ovoid lenticular, 
brown, or purplish when immature, with low but sharp, 
close, wrinkled reticulations, 1.3 to 1.5mm. long, 1.1 to 1.3 
mm. wide, .9 mm. thick; caruncle small, flat and thin. — 
Very variable and with several well-marked varieties. The 
typical form is found from eastern Colorado to south- 
eastern Kansas, and south to Mexico and Alabama. — 
Plate 18. 
Specimens examined from Colorado (Eastwood, Platte Riv. 1892); 
Texas (Lindheimer, 302, 1844-6, 167, 1844, 311, 1845; Wright; Jermy, 
Gillespie Co.; Wurzlow, Industry, 15, 1893; Hall, Houston, 554, 1872, 
the seed resembling that of Z. leiococca; Reverchon, Dallas, 1880; Drum- 
mond, 328; Joor, Navarro Co., 1880, Richland, 1880); Arkansas (Dr. 
Pitcher; Engelmann, 281); Indian Territory (Sheldon, Colberts, 15, 
40, 1891; Engelmann, Cherokee Nation, 1132, 1835; Bush, Coal Creek, 
549, Vinita, 547, 1894; Butler, Limestone Gap, 1877; Bush, Sapulpa, 
548, 1894, 1097, 1895, some of the specimens approaching EZ. obtusata 
in foliage and having red glands); Missouri (Bush, Dodson, 429, 1896, 
near var. Missouriensis); Louisiana (Hale); Alabama (Buckley, 1840; 
Mohr, Russell Co., 6); Mexico (Wright, Lake Sta. Maria; Berlandier, 
2536, 1834). 
A robust, large leaved form with more pubescent invo- 
lucres is represented by Lindheimer, New Braunfels, 
Tex., 88, 1848 (Plate 18); Carleton, Muskogee, I. T., 
20, 1891; and Joor, Navarro Co., Tex., 1880. Heller, 
Corpus Christi, Tex., 147 5, 1894 (EL. obtusata Heller, Bot. 
Expl. South. Tex. 61. 1895), is a peculiar plant with many 
ascending or decumbent branches from a seemingly biennial 
root. — Plate 19. 
Var. MissouRrENsIS n. var. Z. obtusata Torr. Ann. 
Lyc. N. Y. 2:244,. 1828; Cat. Plant. Fremont Exp. 
96. 1845. Euphorbia platyphylla Gray, Pac. R. R. 
Rept. Stevens Exped. 47. 1860. E. dictyosperma 
of most Eastern floras. — Brit. & Brown, Ill. Flora /f. 
2331; Boiss. Euphorb. Icon. pl. 84. 1866. 
Usually larger and more robust than in the typical form ; 
19 
