EUPHORBIACEAE 199 



Plants pubescent. 7. E. dentala. 



Plants glabrous. 

 Plants slender : stems or branches forked. 

 Plants annual : stem branched at the base : leaf-blades inequilateral. 



I. E. polygonifolia. 

 Plants perennial : stems several from a stout root : leaf-blades equi- 

 lateral. &. E. Ipecacuanhas. 

 Plants stout : stem topped by an umbel. 9. E. Lathyris. 

 b. Leaves alternate or scattered. 



Leaf-blades serrulate : involucre with oblong, oval or orbicular glands. 

 Seeds smooth or faintly reticulated. ii. E. piatyphylla. 



Seeds strongly and prominently reticulated. 12. E. Helioscopia. 



Leaf-blades entire : involucre with reniform or crescent-shaped glands. 

 Plants annual or biennial : seeds pitted. 



Capsules with 2-crested lobes. 13. E. Peplus. 



Capsules with rounded lobes. 14. E. comntutata. 



Plants perennial : seeds smooth. 



Glands of the involucre without horns. 10. E. Darlingtonii. 



Glands of the involucre with horns. 



Stem-leaves 4-12 mm. wide : capsules smooth. 



Bracts subtending the umbel lanceolate or oblanceolate. 



15. E. Estila. 

 Bracts subtending the umbel oval or obovate. 



16. E. lucida. 

 Stem-leaves 0.5-3 mni. wide : capsules with granular lobes. 



17. E. Cyparissias. 



1. Euphorbia polygonifolia L. Seaside or Knotweed Spurge. 

 (Man. p. 591 ; I. F. /. -^joy.) In sand along the Atlantic coast, N. H. to 

 Fla., and on the shores of the Great Lakes. — Pennsylvanta : Erie, 

 Presque Isle ; Clinton. 



2. Euphorbia maculata L. Milk Spurge. (Man. p. 592; I. F. /_ 

 2314.) Throughout N. Am., except the e.^treme north. Apparently in- 

 trod. west of the Rocky Mis. — Pennsylvania : Northampton ; Bucks ; 

 Del-^ware ; Chester ; LancasVer ; Franklin ; Allegheny. 



3. Euphorbia hirsuta (Torr. ) Wiegand. Hairy Spurge. (Man. p. 

 592; I. F. /. 2j/4a.) In sand)' or gravelly soil, Quebec and Ont. to 

 Conn., N. Y. and Pa. — Pennsylvania : Northampton ; Bucks ; Lancas- 

 ter ; York ; Crawford. 



4. Euphorbia nutans Lag. Large or Upright Spotted Spurge. 

 (Man. p. 593 ; I. F. _/". .23 /g. ) In fields and thickets throughout eastern 

 N. Am., except the extreme north, extending west to Rocky Mts. — Penn- 

 sylvania : North.ampton ; Del.wvare ; Chester ; Lancaster ; Frank- 

 lin ; Allegheny. 



5. Euphorbia corollata L. Blooming or Flowering Spurge. 

 (Man. p. 593; I. F. y. ^j^/.) In dry soil, Mass. and Ont. to Minn. 

 and Kans., south to Fla. and Tex. — Pennsylvania: Northampton; 

 Bucks ; Delaware ; Chester ; Lancaster ; Allegheny. 



6. Euphorbia marginata Pursh. White-margined Spurge. (Man. 

 p. 594; I. F. /. .2322.) Introd. from the West into waste places in the 



