40 EUPHORBIACEAE 



23. Euphorbia Hooveri L. C. Wheeler. Hoover's Spurge. Fig. 3055. 



Euphorbia Hooveri L. C. Wheeler, Proc. Biol. Soc. Wash. S3 : 9. 1940. 



Annual, glabrous ; stems prostrate or decumbent, 6-20 cm. long. _ Leaves orbicular-cordate to 

 reniform, epidermis papillate, margin with sharp white teeth; stipules united, white, deeply 

 lacerate; cyathia solitary; involucres campanulate, glabrous, 1.7-2 mm. in diameter; glands 

 transversely oval, 0.5 mm. long; fifth gland of mostly 2 filiform segments nearly equaling the 

 lobes ; sinus narrowly V-shaped ; appendages parted into 3-5 white glabrous ligules about 1 mm. 

 long; staminate flowers 30-35; capsules 1.6-1.9 mm. long, roundly 3-lobed, glabrous, spheroidal 

 with flattened base ; seeds white, 1.4-1.6 mm. long, ovoid-quadrangular, rotund-ovate, facets with 

 low faint wrinkles. 



Desiccate beds of subsaline rain-pools. Lower Sonoran Zone; Tehama and Tulare Counties, California. 

 Type locality: Yettem, Tulare County, California. June-July. 



24. Euphorbia maculata L. Large Spurge. Fig. 3056. 



Euphorbia maculata L. Sp. PI. 455. 1753. 

 Euphorbia nutans Lag. Gen. & Sp. Nov. 17. 1816. 

 Euphorbia Preslii Guss. Prodr. Sic. 539. 1827. 

 Chamaesyce maculata Small, Fl. S.E.U.S. 713, 1333. 1903. 

 Chamaesyce nutans Small, op. cit. 712, 1333. 



Annual with stems usually erect, branching, sparsely tomentulose to glabrous, 20-45 cm. long. 



Leaves 7-30 mm. long, oblong to oblong-lanceolate, very sparsely villous, serrate ; stipules more 



or less united, free portion subulate, with a few hairs ; cyathia congested at the branch-tips ; 



involucres 0.75-1 mm. in diameter, slenderly obconic, glabrous ; glands long-stipitate, circular 



to transversely broadly elliptical, 0.1-0.2 mm. in diameter ; fifth gland linear ; sinus U-shaped, 



little depressed ; appendages rudimentary to 0.5 mm. long, oval, white to reddish, glabrous, entire ; 



staminate flowers 5-11 ; capsule glabrous, sharply 3-angled, depressed-globose, 2 mm. long; seeds 



dark gray, 1.1-1.3 mm. long, broadly oblong-ovate, angles rounded, facets wrinkled. 



In the foothills and in waste places in the valleys, Lower and Upper Sonoran Zones; sparingly introduced 

 in the Pacific States (Skamania County, Washington, Sierra Nevada foothills and Orange County, California); 

 native of eastern United States and Mexico. Type locality: "America septentrionalis." April-Sept. 



25. Euphorbia arizonica Engelm. Arizona Spurge. Fig. 3057. 



Euphorbia arizonica Engelm. Bot. Mex. Bound. 186. 1859. 

 Euphorbia versicolor Greene, Bot. Gaz. 6: 184. 1881. 

 Euphorbia portulana S. Wats. Proc. Amer. Acad. 24: 75. 1889. 

 Euphorbia purisimana Millsp. Proc. Calif. Acad. II. 2: 225. 1889. 



Perennials, stems erect or prostrate, 15-30 cm. long, slender, with fine spreading hairs. 

 Leaves 2-10 mm. long, deltoid-ovate to ovate-oblong, entire, mostly finely pubescent; stipules 

 minute ; cyathia solitary ; involucres slenderly urceolate, 0.8 mm. in diameter, sparsely pubescent ; 

 glands transversely oblong, 0.3-0.4 mm. long, red ; appendages glabrous, entire to crenate, con- 

 spicuous, white but rubescent in age; fifth gland absent; sinus V-shaped, depressed halfway to 

 base of involucre; staminate flowers 5-10, rarely 12; capsule pubescent, obtusely 3-angled, 1.5 

 mm. long, globose-ovoid; seeds quadrangular, 1.1-1.2 mm. long, narrowly ovate, facets with low 

 ridges slightly including the angles, coat whitish. 



Sandy desert flats, Lower Sonoran Zone; v/estern borders of Coachella Valley and Colorado Desert, Cali- 

 fornia, east to Texas, south to Sonora and Durango. Type locality: Arizona.* March-Oct. 



26. Euphorbia setiloba Engelm. Yuma Spurge. Fig. 3058. 



Euphorbia setiloba Engelm. Pacif. R. Rep. 5: 364. 1858. 



Chamaesyce setiloba Millsp. in Parish, Cat. PI. Salton Sink 6. 1913. Preprint from Carnegie Inst. Wash. 

 Pub. No. 193: 110. 1914. 



Euphorbia floccosiuscula M. E. Jones, Contr. West. Bot. No. IS: 145. 1929. 



Annual, stems prostrate, villous, 6-15 cm. long, ultimate branchlets often with leaves and 



cyathia congested into dense small heads. Leaves 3-7 mm. long, oblong to oblong-ovate, entire, 



villous ; stipules rudimentary ; cyathia solitary ; involucres 1 mm. in diameter, pubescent, slenderly 



urceolate; glands red, transversely oblong or the distal sometimes circular, 0.1-0.2 mm. long; 



fifth gland totally absent; sinus depressed halfway to base of involucre; appendages white, 



glabrous, about 1 mm. long and wide, parted into 3-5 narrow attenuate segments ; staminate 



flowers 3-7 ; capsule sharply 3-angled, villous, globose, 1.2 mm. long ; seeds brownish white, 0.9-1 



mm. long, ovate-acutish, quadrangular, angles sharp, facets with low irregular wrinkles. 



Sandy desert washes and flats, Lower Sonoran Zone; Inyo County south to San Diego and Imperial Coun- 

 ties, California, east to Nevada and western Texas, south to Lower California and Sinaloa. Type locality: 

 Fort Yuma, Imperial County, California. Jan.-May. 



27. Euphorbia pediculifera Engelm. Louse Spurge. Fig. 3059. 



Euphorbia pediculifera Engelm. Bot. Mex. Bound. 186. 1859. 

 Euphorbia conjuncta Millsp. Proc. Calif. Acad. II. 2:227. 1889. 

 Euphorbia invotuta Millsp. loc. cit. 

 Euphorbia vermiformis M. E. Jones, Contr. West. Bot. No. 16: 23. 1930. 



Perennial, stems usually prostrate, 15-30 cm. long, appressed-pubescent. Leaves ovate to 

 lanceolate, entire, densely appressed-pubescent to glabrate, 4-22 mm. long ; stipules short, ventral 



