EUPHORBIACEAE. 



Leaves toothed, but sometimes only at the apex. 

 Capsule, stem and leaves glabrous. 



Seeds strongly transversely wrinkled. 8. C. glyptosperma. 



Seeds pitted or irregularly and faintly wrinkled. 



Seeds deeply and irregularly pitted. 9. C. rugulosa. 



Seeds faintly pitted or wrinkled. 



Leaves oblong ; seeds usually with a white bloom. 



10. C. serpyllifolia. 

 Leaves linear; seeds brownish, usually without bloom. 



11. C. albicaulis. 

 Capsule, stem and leaves pubescent. 12. C. stictospora. 



1. Chamaesyce serpens (H. B. K.) Small. (Euphorbia serpens H. B. K.) 

 On prairies from Ont. and S. D. to Fla. and Ariz. ; also Mex. New Windsor, 

 Weld Co. 



2. Chamaesyce revoluta (Engelm.) Small. (E. revolnta Engelm.) On hill- 

 sides from Tex. and Colo, to N. M. ; also northern Mex. Canon City. 



3. Chamaesyce petaloidea (Engelm.) Small. (E. petaloidea Engelm.) On 

 prairies and hillsides, especially in sandy soils, from Iowa and Wyo. to Tex. 

 and Colo. Alt. 4000-7000 ft. Boulder ; La Veta ; Crow Creek ; Longmont ; 

 Boulder Canon. 



4. Chamaesyce flagelliformis (Engelm.) Rydb. (E. petaloidea flagelliformis 

 Engelm.; E. flagelliformis Engelm.) In dry soil from Colo, to Tex. and N. 

 M. " Southwestern Colorado." 



5. Chamaesyce albomarginata (T. & G.) Small. (E. alb o mar gin at a T. & 

 G.) In dry soil from Colo, and Utah to Tex. and Calif.; also Mex. Upper 

 Platte. 



6. Chamaesyce Fendleri (T. & G.) Small. (E. Fendleri T. & G.) On 

 dry hills, in sandy soil, from Neb. and Wyo. to Tex. and Ariz. Alt. 4000-6000 

 ft. Foot-hills near Boulder; Trinidad; Canon City; Black's Lake; Cedar 

 Hills. 



7. Chamaesyce lata (Engelm.) Small. (E. lata Engelm.) On plains and 

 prairies from Kans. and Colo, to Tex. and N. M. " Southwestern Colorado." 



8. Chamaesyce glyptosperma (Engelm.) Small. (E. glyptosperma Engelm.) 

 In sandy soil from Ont. and B. C. to Tex. and Mex. Alt. 4000-7000 ft. 

 Colorado Springs; Denver; Deer Run; Canon City: Pueblo; Boulder; Fort 

 Collins ; Manitou ; New Windsor ; gulch west of Soldier Canon ; Miller's 

 ranch, between Fort Collins and La Porte ; Horsetooth Gulch. 



9. Chamaesyce rugulosa (Engelm.) Rydb. (E. serpyllifolia rugulosa 

 Engelm.) In sandy soil from Wyo. to N. M. and Calif. Mountains between 

 Sunshine and Ward ; gulch west of Soldier Canon ; between Porter and 

 Durango. 



10. Chamaesyce serpyllifolia (Pers.) Small. (E. serpyllifolia Pers.) In 

 dry soil from Mich, and Wash, to Tex. and Calif. ; also Mex. Alt. 4000-8000 

 ft. Antonito ; Lyons ; Arboles ; Gunnison ; Durango ; Manitou ; Parlin ; 

 Boulder Co.; Box Canon west of Ouray; between Fort Collins and La Porte; 

 Rocky Ford. 



11. Chamaesyce albicaulis Rydb. (E. albicaulis Rydb.) In old fields and 

 sandy soil from Neb. and Mont, to N. Mex. Alt. 4000-5500 ft. Foot-hills 

 west of Fort Collins. 



