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EUPHORBIACEAE. 
Family 78. EUPHORBIACEAE St. Hill. Spurge Family. 
Flowers not in an involucre; calyx of several sepals. 
Petals present, at least in the staminate flowers. 
Stamens 6; filaments distinct. 1. Croton. 
Stamens 10; filaments monadelphous. 2. Ditaxis. 
Corolla wanting; stamens 1-3. 3- Tragia. 
Flowers in involucres; calyx represented by minute scales at the base of filament¬ 
like pedicels. 
Glands of the involucres with petal-like appendages; these however sometimes 
much reduced. 
Leaves all opposite. 
Glands of the involucres 4; leaves inequilateral, usually oblique at the base. 
4. Chamaesyce. 
Glands of the involucres 5 ; leaves equilateral, not oblique at the base. 
5. Zygophyllidium. 
Leaves alternate or scattered, at least below the inflorescence; bracts petal¬ 
like. 6. Dichrophyllum. 
Glands of the inflorescence without petal-like appendages; entirely naked 
or with a crescent-like horn. 
Stem topped by an umbel; stipules none; involucres in open cymes, each 
with 4 glands and entire or toothed lobes. 7. Tithymalus. 
Stem not topped by an umbel; stipules gland-like; involucres in cluster-like 
cymes; each with a single gland or rarely with 4 glands and fimbriate lobes. 
8. Poinsettia. 
1. CROTON L. 
1. Croton texensis (Klotzsch) Muell. Arg. In sandy soil from Ill. and 
Wyo. to Ala. and Ariz.; also in Mex.—Alt. 4000-6000 ft.—New Windsor; 
Crow Creek; Canon City; Longmont; Boulder; La Salle. 
2. DITAXIS Vahl. 
1. Ditaxis humilis (Engelm. & Gray) Pax. (Argythamnia humilis Muell.) 
On prairies from Kans. and Colo, to La. and Tex.—“ Southern Colorado.” 
3. TRAGIA. 
1. Tragia ramosa Torr. In dry soil from Mo. and Colo, to Tex. and Ariz.; 
also Mex.-—Alt. 4000-6000 ft.—Boulder; Denver; Castle Rock; Larimer Co.; 
Arboles; Walsenburg; Trinidad; Horsetooth Gulch; Spring Canon; gulch 
west of Pennock’s; Ute Creek; Pennock’s; Spring Canon. 
4. CHAMAESYCE S. F. Gray. Spurge. 
Leaves entire. 
Annuals or biennials. 
Plants prostrate; leaf-blades nearly orbicular. 1. C. serpens. 
Plants more or less ascending or erect; leaf-blades linear or linear-lanceolate. 
Capsule less than 1.5 mm. long. 2. C. revoluta. 
Capsule about 2 mm. long or more. 
Appendages of the glands conspicuous, white. 3. C. petaloidea. 
Appendages inconspicuous, greenish-white, or obsolete. 
4. C. flagelliformis. 
Perennials. 
Leaves glabrous. 
Glands transversely oval; appendages fan-shaped, white, petalloid. 
5. C. albomarginata. 
Glands oval; appendages crescent-shaped, much narrower than the gland, 
greenish. 6. C. Fendleri. 
Leaves pubescent. 7. C. lata. 
