GENUS 12. 



CROWFOOT FAMILY. 



95 



4. Delphinium Nelsoni Greene. 

 Larkspur. Fig. 1873. 



Nelson's 



Delphinium Nelsoni Greene, Pittonia 3: 92. 1896. 



Finely puberulent, at least above ; stem slender, 

 simple, 8'-i high from a cluster of tuberous roots 

 near the surface of the ground. Leaves firm, the 

 lower pedately divided into linear lobes or segments, 

 long-petioled, the petioles sheathing the stem, the 

 upper short-petioled, less divided ; flowers in the 

 upper axils and forming a loose terminal raceme, 

 blue, slightly villous, slender-pedicelled; lower pedi- 

 cels i '-2' long, longer than the flowers; sepals ob- 

 long, shorter than the slender spur; lower petal 

 2-cleft, with a tuft of hairs about the middle; folli- 

 cles 3, appressed-pubescent ; seeds wing-angled 

 above. 



Western Nebraska and Colorado to Wyoming, and 

 British Columbia. May-June. 



5. Delphinium carolinianum Walt. 

 Carolina Larkspur. Fig. 1874. 



D. carolinianum Walt. Fl. Car. 155. 1788. 

 D. aziireum Michx. Fl. Bor. Am. i : 314. 1803. 

 Delphinium Nortonianum Mackenzie & Bush, 

 Trans. Acad. St. Louis 12 : 82. 1902. 



Stem slender, more or less pubescent, 

 i-2 high. Leaves deeply cleft into linear 

 toothed or cleft segments; raceme ter- 

 minal, 4'-8' long; flowers pedicelled, blue, 

 about i' long, the spur curved upward, 

 horizontal or nearly erect, 8" long; fol- 

 licles 3, erect or slightly spreading, downy, 

 7 "-9" long, tipped with a subulate beak; 

 seed coat rugose. 



Prairies and open grounds, Virginia to Mis- 

 souri, Florida and Texas. Prairie, blue or 

 azure larkspur. May-July. 



6. Delphinium virescens Nutt. Prairie Lark- 

 spur. Fig. 1875. 



D. virescens Nutt. Gen. 2: 14. 1818. 



D. albcscens Rydberg, Bull. Torr. Club 26: 583. 1899. 



Perennial, with branched woody roots, pubescent and 

 often somewhat glandular. Stem stout, i-3 high; leaf- 

 segments linear, i"~3" wide; raceme narrow, rather 

 densely flowered ; lower pedicels sometimes 2' long, the 

 upper much shorter; flowers white, or bluish-white, 

 finely pubescent ; spur horizontal or ascending, 6"-8" 

 long, straight, or slightly curved upward; follicles 6"- 

 9" long, erect, puberulent. 



Prairies, Illinois to Minnesota, Manitoba, Kansas and 

 Texas. D. Penardi Huth, of the Rocky Mountains, is closely 

 related to this species. May-July. 



