SPURGE FAMILY 545 



appendages white, crescent-shaped, crenulate; pod 2 mm. thick; seeds light olive- 

 brown, oblong, acutely 4-angled, 1.3-1.5 mm. long, less than 0.5 mm. broad. E. 

 albicauiis Rydh. Cultivated or sandy soil: Neb. — Mont. — N.M. Plain. Jl-Au. 



15. C. maculata (L.) Small. Plant dark green; stems 5-40 cm. long, often 

 dark red, villous; leaf-blades oblong or ovate-oblong, 4-16 mm. long, more or 

 less serrate, usually blotched, oblique, semi-cordate at base; involucres 1 mm. 

 long; appendages semiorbicular, white, crenulate; capsules about 2 mm. thick, 

 pubescent; seeds ovoid-oblong, less than 1 mm. long, obtusely angled, ash-colored, 

 minutely pitted and inconspicuously transversely wrinkled. E. maculata L. 

 Drv ground and waste places: Ont. — -Fla. — Tex. — Wyo.; introduced in Calif. 

 Plnin. Mr-0. 



16. C. stictospora (Engelm.) Small. Plant yellowish green; stems 5-30 cm. 

 long, villous; leaf^blades oblong to suborbicular, densely villous, 4-6 mm. long, 

 obtuse, dentate-serrate above the middle; involucres campanulate, 1 mm. high; 

 appendages narrow, crescent-shaped; capsules 1.5-2 mm. in diameter; seeds 

 narrowly ovoid, 1.2-1.5 mm. long, pointed, pitted, ash-colored, sharply angled. 

 £". s/ido.spora Engelm.' Dry soil: Kans. — Colo.- — Ariz. — Tex. — Mex. Son. Ap-N. 



5. ZYGOPHYLLIDIUM Small. Spurge. 



Annual herbs, with erect, forking stems. Leaves mostly opposite, narrow, 

 equilateral, not oblique at the base. Stipules gland-like, often obsolete. Invo- 

 lucres short-peduncled in the upper forks. Glands 5, broader than long, with 

 petal-like appendages. Capsule long-pedicelled, 3-lobed. Seeds terete, nar- 

 rowed upwards, more or less papillose. 



Leaves entire; appendages of the glands triangular-ovate. 1. Z. hexagonum. 



Leaves serrate; appendages of the glands semi-orbicular. 2. Z. exstipulatum. 



1. Z. hexagonum (Nutt.) Small. Plant yellowish green; stem slender, 1-5 

 dm. high, with ascending almost filiform branches; leaves linear, oblong, or 

 lanceolate, short-petioled; involucres 2-3 mm. long, ciliate; appendages green 

 or whitish; capsule 4 mm. thick; seeds ovoid or oblong, 3 mm. long, terete, 

 papillose. Euphorbia hexagona ISlutt. On sandy prairies and river valleys : la. — 

 Tex.— N.]\I.— Mont. Plain. Jl-S. 



2. Z. exstipulatum (Engelm.) Woot. & Standi. Plant light green; stem 

 erect, branched, glabrous, 1-3 dm. high; leaf -blades linear to lanceolate or on 

 the branches ovate, sharply serrate, 1-3 cm. long, glabrous; involucres fully 1 

 mm. high; appendages white, 2-4-lobed; capsule rounded, 3 mm. thick; seeds 

 ash-colored, tubercled and with 2-3 cross ridges, round-angled, 2 mm. long. E. 

 exslipulata Engelm. E. Aliccae A. Nels. Dry regions: Wyo. — Tex. — Ariz. 

 Son. — Submont. Au-S. 



6. LEPADENIA Raf. Snow-on-the-mountain. 



Annual herbs, with erect stems. Leaves scattered below the umbel-like in- 

 florescence, often very showy and petal-like in the inflorescence. Stipules fuga- 

 ceous. Involucres campanulate; lobes fimbriate. Glands 5, peltate, with pink 

 or white petal-like appendages. Capsule 3-lobed, j)ubescent, round-lobed. 

 Seeds narrowed upwards, reticulate. [Dichropkyllum Kl. & Garke.] 



1. L. marginata (Pursh) Niewl. Stout annual; stem 3-9 dm. tall, usually 

 pilose; leaves ovate or obovate, 2-9 cm. long, sessile; bracts large, white-margined; 

 involucres campanulate, 4 mm. long, usually pubescent; appendages reniform, 

 white; capsule depressed-globose, 6 mm. in diameter, usually pubescent; seeds 

 ovoid-globose, terete, 4 mm. long, dark ash-colored, reticulate-tuberculate. E. 

 vinrginata Pursh. Dicrophyllum marginatum (Pursh) Kl. & Garke. Prairies, 

 ])lains, and river valleys: Minn. — Tex. — Colo. — Mont.; introduced eastward. 

 Plain — Submont. Jl-S. 



7. TITHYMALUS (Tourn.) Adans. Spurge. 



Annual or perennial herbs, rarely shrubby, with simple or branched stems. 

 Leaves below the inflorescence scattered, without stipules, entire or toothed, 



