34 EUPHORBIACEAE 



lower petioled; umbel-leaves oblong-spatulate, sessile, 1-2.5 cm. long; floral leaves ovate-elliptic, 

 sessile ; involucres glabrous, 1 mm. in diameter, broadly campanulate ; glands transversely oblong, 

 entire, 0.5-0.7 mm. long; fifth gland absent; sinus very broad, undepressed, ciliate; staminate 

 flowers 5-8; capsule verrucose especially toward the apex, glabrous, 2.5 mm. long, depressed- 

 globose, roundly 3-lobed; seeds brown, 2 mm. long, lenticular-ovoid, superficially reticulate. 



Hill country. Upper Sonoran Zone; southern Washington, western Oregon and cismontane California, east 

 to Iowa and Alabama; probably introduced in Argentina and Uruguay. Type locality: Montevideo, Uruguay. 

 March-July. 



6. Euphorbia Peplus L. Petty Spurge. Fig. 3038. 



Euphorbia Peplus L. Sp. PI. 456. 1753. 

 Tithymalus rotundifolius Lam. Fl. Franc. 3: 100. 1783. 

 Tithymalus Peplus Gaertner, Fruct. 2: 115. 1791. 

 Esula Peplus Haw. Syn. PI. Succ. 158. 1812. 



Glabrous annual, 10-45 cm. tall ; stems 1 to several, erect or ascending, simple or branched 

 below the umbel; rays 3, repeatedly dichotomous. Leaves entire, thin; stem-leaves 1-3.5 cm. 

 long, rotund to obovate, petioled, umbel-leaves similar ; floral leaves ovate, base cordate, sessile, 

 distinct, to 2 cm. long; involucre glabrous, 1 mm. in diameter, campanulate; glands crescentic, 

 body broad, 0.3 to 0.5 mm. long, with 2 slender spreading horns, otherwise entire; fifth gland 

 short, deltoid, hairy; sinus U-shaped, depressed; staminate flowers 10-15; capsule glabrous, 2 

 mm. long, depressed-globose, sharply 3-angled, carpels bicarinate on back; seeds white, 1.3 mm. 

 long, subhexagonal, oblong, ventral facets with 2 dark longitudinal grooves, lateral and dorsal 

 facets each with a longitudinal row of 2-4 dark pits. 



Mostly in well-watered sites about shrubbery, introduced from Europe, Upper Sonoran Zone; western 

 Washington, western Oregon, and rare in the San Joaquin Valley, common near the coast in California. Type 

 locality: Europe. Feb.-Aug. 



7. Euphorbia crenulata Engelm. Chinese Caps. Fig. 3039. 



Euphorbia leptoccra Engelm. Pacif. R. Rep. 4: 135. 1856. (Nomen nudum.) 



Euphorbia crenulata Engelm. Bot. Mex. Bound. 192. 1859. 



Euphorbia crenulata var. franciscana Norton, No. Amer. Euphorbia sect. Tithymalus 38. 1899. Preprint 



from Rep. Mo. Bot. Card. U: 122. 1900. 

 Euphorbia Nortoniana A. Nels. Bot. Gaz. 47 : 437. 1909. 



Glabrous annual or biennial, 12-50 cm. tall ; stems 1 to several, erect or declined at base, 

 often branched below the umbel ; rays mostly 5, sometimes 3 or 4, 2-3 times dichotomous. Leaves 

 entire or occasionally irregularly crenulate ; stem-leaves obovate to spatulate, petiolate to sub- 

 sessile, 1-3.5 cm. long; umbel-leaves rhombic-obovate to obovate, sessile, 1-3.5 cm. long; floral 

 leaves deltoid-ovate to oval-reniform, sessile, more or less connate, to 2.5 cm. long; involucres 

 turbinate-campanulate, 2 mm. in diameter, glabrous ; glands crescentic, body thick, 1-2 mm. long, 

 horns usually long, slender ; fifth gland narrowly deltoid, moderately long ; sinus U-shaped, 

 slightly depressed; staminate flowers 11-18; capsule glabrous, 3.5 mm. long, oblong-cyjindrical, 

 roundly 3-lobed; seeds mottled, cinereous, 2.2-2.5 mm. long, oblong-ovoid, with low irregular 

 vermiculate ridges. 



In shady sites in the foothills, Upper Sonoran and Transition Zones; Oregon, south through cismontane 

 California to Orange County, east to Colorado. Type locality: near Monterey, California. March-July. 



8. Euphorbia incisa Engehn. Mojave Spurge. Fig. 3040. 



Euphorbia incisa Engelm. in Ives, Rep. 4: 27. 1860. 

 Euphorbia schizoloba Engelm. Proc. Amer. Acad. 5: 173. 1861. 

 Tithymalus schisolobus Norton, Contr. U.S. Nat. Herb. 25: 343. 1925. 



Glabrous, glaucous perennial ; stems very numerous from the root crown ; slender, erect or 

 ascending, 20-40 cm. long, often branched below the umbel ; rays mostly 5, sometimes 3-4, 2-3 

 times dichotomous. Leaves entire, thick; stem-leaves ovate-elliptic to broadly oblanceolate, 1-2 

 cm. long, short petiolate, mucronate; umbel-leaves long-oval to elliptic-ovate, sessile, 1-1.5 cm. 

 long; floral leaves deltoid-oval to cordate, sessile, sometimes puberulent at base, to 1 cm. long; 

 involucres campanulate, glabrous, 2.5 mm. in diameter; glands broadly transversely oblong to 

 oblong-crescentic, 2-3 mm. long, short-horned or hornless, margin lacerate to crenate ; staminate 

 flowers 16-23, sparsely pubescent to glabrous ; capsule glabrous, 4 mm. long, oblong-ovoid, 

 roundly 3-lobed ; seeds white to sordid, 3 mm. long, oblong-ovoid, with very low vermiculate 

 ridges. 



Arid slopes, and rarely in low washes, Lower and mostly Upper Sonoran Zones; desert ranges in Inyo and 

 San Bernardino Counties, rare in the Colorado Desert, California, east to Nevada and Arizona. Type locality: 

 Railroad Pass, Cerbat Mountains, Mohave County, Arizona. March-June. 



9. Euphorbia Palmeri Engelm. Wood Spurge. Fig. 3041. 



Euphorbia Palmeri Engelm. Bot. Calif. 2: 75. 1880. 

 Tithymalus Palmeri Abrams, Fl. Los Ang. 216. 1917. 



Glabrous, glaucous perennial, 15-30 cm. tall; stems ascending to erect, numerous from the 

 woody root crown, mostly simple below the umbel ; rays mostly 5, sometimes 3 or 4, 1-3 times 

 dichotomous. Leaves thick, entire; stem-leaves narrowly obovate to oblong-spatulate, 1-2 cm. 

 long, sessile or shortly petiolate, grading downward into crowded early-deciduous scales on 

 subterranean portion of stem; umbel-leaves broadly rhombic to rhombic-cordate, sessile, 1—1.8 

 mm. long ; floral leaves oval-cordate to oval-spatulate, to 1 cm. long ; involucres campanulate, 

 glabrous, 2 mm. in diameter; glands 1.2-2 mm. long, broadly crescentic, very short horned, 



