SPURGE FAMILY 543 



naked or usually with an appendage; one sinus of each involucre usually gland- 

 less. Capsule 3-lobed, smooth, with sharp or rounded angles. Seeds angled, 

 the faces smooth or transversely wrinkled. 



Leaf-blades entire. 



Annuals or biennials. 



Plants prostrate; leaves oblong to orbicular. 



Leaf-blades manifestly longer than broad, usuaUy more than twice as long. 



1. C. Geyeri. 



Leaf-blades as broad as long or nearly so. 2. C. serpens. 



Plants more or less ascending or erect; leaf-blades Unear or linear-lanceolate. 

 Capsule less than 1.5 mm. long. 3. C, revoluta. 



Capsule about 2 mm. long or more. 



Appendages of the glands conspicuous, white. 4. C. petaloidea. 



Appendages inconspicuous, greenish white, or obsolete. 



Stems low and erect; stipules subulate-setaceous; seeds finely granu- 

 late, obscurely angled. 5. C. Parryi. 

 Stems long and ascending; stipules triangular; seeds smooth, 3-angled. 



6. C. flagelliformis. 



Perennials. 



Leaves glabrous. 



Appendages fan-shaped, white, petaloid; stipules triangular, fimbriate. 



7. C. albomarginata. 

 Appendages crescent-shaped or semi- orbicular, greenish, pinkish, or yellowish; 



stipules subulate-setaceous. 

 Appendages crescent-shaped, much narrower than the gland; leaves broadly 

 deltoid-ovate; seeds transversely ridged; plant prostrate. 



8. C. Greenei. 



Appendages conspicuous, semi-orbicular, fully as broad as the glands; 

 leaves ovate or ovate-lanceolate; seeds irregularly pitted; plant erect. 



9. C. Fendlen, 



Leaves pubescent. 10. C. lata. 



Leaves toothed, but sometimes only at the apex; stems and branches prostrate; annuals. 

 Capsules glabrous. 



Seeds strongly transversely wrinkled. 11. C. glyptosperma. 



Seeds pitted or irregularly and faintly wrmkled. 



Seeds deeply and irregularly pitted. ' 12. C. rugulosa. 



Seeds faintly pitted or wrinkled. 



Leaves oblong; seeds usually with a wliite bloom. 13. C. serpyllifolia. 



Leaves linear; seeds brownish, usually without a bloom. 



14. C. alhicaulis. 



Capsule pubescent. 



Leaf-blades and involucres glabrous or sparingly pubescent. 15. C. maculata. 

 Leaf-blades and involucres copiously hirsute. 16. C. stictospora. 



1. C. Geyeri (Engelm.) Small. Plant green; stem branched at the base; 

 branches 0.5-4 dm. long; leaf-blades oblong to ovate, 4-12 mm. long, obtuse, 

 usually mucronulate, truncate or subcordate at the base; involucres turbinate, 

 1.5 mm. high; glands 0.3 mm. broad; appendages inconspicuous, white or red; 

 seeds narrowly ovoid, 1.5 mm. long, nearly terete, ash-colored. Euphorbia 

 Geyeri Engelm. On plains and prairies: 111. — Mo. — Tex. — Xeb. — Minn. 

 Plain. Je-S. 



2. C. serpens (H.B.K.) Small. Plant pale green; stems branched at the 

 base, 5-30 cm. long; leaf-blades orbicular to oval, 2-6 mm. long, obtuse or emargin- 

 ate, rounded or subcordate at the base; involucres nearly 1 mm. high; appendages 

 minute, irregular, crenate; capsules nodding, depressed-globose, 2 mm. broad; 

 seeds 1 mm. long, smooth, obtusely 4-angled, light gray. E, serpens H.B.K. 

 On prairies and plains: Ont. — Fla. — Ariz.— S.D.; Mex. Plain — Son, Je-O. 



3. C, revoluta (Engelm.) Small, Plant delicate; stem very slender, 8-20 

 cm. high; leaves few; blades narrowly Unear, 1-3 cm. long, usuaUy about 1 mm. 

 broad, acute; involucres 1 mm. long; glands minute, broader than long, purple; 

 appendages white or reddish, oblong or ovate, obtuse, entire; capsules about 1 

 mm. long, rather sharply 3-angled; seeds oblong, less than 1 mm. long, sharply 

 4-angIed, the faces irregularly wrinkled. E, revoluta Engelm. Hillsides: Tex. — 

 Colo. — N.M.; nMex. Son, Jl-Au. 



4. C. petaloidea (Engelm.) Small. Plant pale green; stem 1-6 dm. high; 

 leaf-blades linear, oblong or Unear-lanceolate, 1-2.5 cm. long, obtuse; involucres 

 oblong-campanulate, 2 mm. long; glands about as long as the lobes; appendage 

 white, reniform, ovate or suborbicular, entire or undulate; capsules globose- 

 reniform, fully 2 mm. long; seeds oblong-ovoid, nearly 2 mm. long, ash-colored. 



