EUPHORBIACEAE 199 



Plants pubescent. 7. E. denlala. 



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. 8. E. Ipecacuanhae. 

 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. 11. E. plalyphylla. 

 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. commutata. 

 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. Esula. 

 Bracts subtending the umbel oval or obovate. 



16. E. lucida. 

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



17. E. Cyparissias. 



1. Euphorbia polygonifolia L. Seaside or KnoTweed Sptirge. 

 (Man. p. 591 ; I. F. /. 230;^.) In sand along the Atlantic coast, N. H. to 

 Fla., and on the shores of the Great Lakes. — Pennsylvania: ERIE, 

 Presque Isle ; Ci,inXon. 



2. Euphorbia maculata L. Mii,k; Spurge. (Man. p. 592 ; I. F. /. 

 2314.) Throughout N. Am., except the extreme north. Apparently in- 

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

 Delaware ; ChestSr ; Lancaster ; Frankwn ; Allegheny. 



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

 592 ; I. F. /. sj/^a. ) In sandy or gravelly soil, Quebec and Out. 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. _/. 2319.) In fields and thickets throughout eastern 

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

 sylvania : Northampton ; Delaware ; Chester ; Lancaster ; Frank- 

 lin ; Allegheny. 



5. Euphorbia coroUata L. Blooming or Flowering Spurge. 

 (Man. p. 593 ; I. F. _/! 232^-') 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 Parsh. White-margined Spurge. (Man. 

 p. 594 ; I. P. y; 2322.) Introd. from the West into waste places in the 



