544 EUPHORBIACEAE 



minutely pitted, nearly terete. E. petaloidea Engelm. Plains, in sandy soil: 

 la. Mont. Tex. Plain. Jl-S. 



6. C. Parry! (Engelm.) Rydb. Plant pale; stems slender, about 1 dm. high; 

 leaf-blades linear, acute or acutish at both ends, 1-2 cm. long, 1-2 mm. wide, 

 rolled inward when drying; involucres 1.5-2 mm. long; appendages unequal, 

 small, greenish, truncate; capsules sharp-angled; seeds 1.5 mm. long, ovate. E. 

 Parryi Engelm. Loose sand: se Utah Nev. L. Son. 



6. C. flagelliformis (Engelm.) Rydb. Plant glabrous, pale; stems prostrate 

 or ascending, branched, 1-4 dm. long; leaf -blades linear or oblong-linear, entire, 

 acutish at both ends, 8-15 mm. long, 2 mm. wide; involucres broadly campanu- 

 late; glands 2-4, concave; appendages obsolete or a mere margin; capsule broadly 

 triangular; seeds gray, acute. Sandy valleys: N.M. Colo. Utah Ariz. 

 Son. 



7. C. albomarginata (T. & G.) Small. Plant glabrous; stems diffusely 

 branched from the base, 2-15 cm. long; leaf -blades suborbicular or ovate-orbicu- 

 lar, 4-8 mm. long, truncate or subcordate at the base; involucres fully 1 mm. high; 

 glands transversely oval; appendages irregular, entire or lobed; capsule globose- 

 ovoid, 2 mm. long, sharply 3-angled; seeds oblong-ovoid, 1-1.3 mm. long. E. 

 albomarginata T. & G. Dry soil: Tex. Colo. Utah Calif .; Mex. Son. Mr-N. 



8. C. Greenei (Millsp.) Rydb. Perennial from a woody root; stems numer- 

 ous, prostrate, diffuse, branched, 1-2 cm. long; leaves 4-7 mm. long and nearly 

 as broad, glabrous, very oblique; involucres 1.5-2.5 mm. long; glands thick, 

 purple; appendages thick, minutely 2-lobed; capsules 2.5-3 mm. thick; seeds 

 ovoid, white, angled. E. Greenei Millsp. Confused with C. Fendleri, Dry or 

 sandy plains: Neb. Wyo. Colo. Ida. Plain Submont. Je-Au. 



9. C. Fendleri (T. & G.) Small. Plant cespitose, usually pale green; stems 

 erect or ascending, about 1 dm. high; leaf-blades ovate to lance-ovate, 4-6 mm. 

 long, 2-5 mm. wide; involucres 1.5-2.5 mm. high; appendages yellowish or 

 purplish, often crenate-toothed ; capsule 3 mm. in diameter; seeds ovoid, 1.5 mm. 

 long. E. Fendleri T. & G. Plains: Tex. Ariz. Utah. Son. Ap-O. 



10. C. lata (Engelm.) Small. Stems branched from a woody root, spread- 

 ing or ascending, 5-15 cm. long, pubescent; leaf -blades ovate to lanceolate, 5-10 

 mm. long, canescent-pubescent, revolute-margined ; involucre 1 mm. long; ap- 

 pendages narrowly crescent-shaped, undulate; capsule rounded 3-angled, 2 mm. 

 thick; seeds oblong, 1.5 mm. long, 4-angled and transversely wrinkled. E. lata 

 Engelm. Plains: Kans. Tex. N.M. Colo. Son. 



11. C. glyptosperma (Engelm.) Small. Plant pale green, glabrous; stem 

 0.5-4 dm. long; leaf-blades oblong, linear-oblong, or rarely ovate, 2-12 mm. long, 

 obtuse or subcordate at the base, serrulate towards the apex; involucres 1 mm. 

 long, with 4 dark ribs; appendages narrow, crescent-shaped, often crenulate; 

 capsule less than 2 mm. thick; seeds oblong, 1 mm. long, ash-colored, strongly 

 4-angled. E. glyptosperma Engelm. Sandy soil: Ont. Mo. Tex. Mex. 

 B.C. Plain Submont. My-S. 



12. C. rugulosa (Engelm.) Rydb. Plant light green; leaf-blades oblong, 

 elliptic, or oval, 5-8 mm. long, semi-cordate at base, serrulate above the middle; 

 involucres turbinate-campanulate, 1 mm. long; appendages whitish, broadly 

 crescent-shaped or semi-orbicular, usually lobed; capsule 1.5-2 mm. thick; seeds 

 oblong-ovoid, obtusely angled, ashy, with purplish pits, nearly 1 mm. long. E. 

 serpyllifolia rugulosa Engelm. Sandy soil: s Calif. Wyo. Colo. Je-O. 



13. C. serpyllifolia (Pers.) Small. Plant dark green or reddish; stems 1-4 

 dm. long; leaf -blades oblong or spatulate, 3-12 mm. long, obtuse or retuse, 

 serrulate above the middle or nearly entire; involucres more than 1 mm. long; 

 appendages narrow, crescent-shaped, lobed; capsules 2 mm. broad; seeds ovoid, 

 hardly 1 mm. long, obtusely 4-angled. E. serpyllifolia Pers. Plains and in dry 

 soil: Mich. Tex. Calif. B.C. Alta.; Mex. Plain Submont. Ap-O. 



14. C. albicaulis Rydb. Plant pale green; stems straw-colored or light 

 greenish yellow, shining; leaf-blades linear, minutely callous-toothed towards 

 the apex, 1-1.5 cm. long, 2-3 mm. wide; involucres about 1 mm. long, turbinate 



