432 MINNESOTA BOTANICAL STUDIES. 



The recent extended articles on the genus are : A. Gray, 

 " An attempt to Distinguish Between the American Delphin- 

 iums," Bot. Gaz. 12 : 49-54, 1887 ; and Syn. Fl. I : 45-52, 

 1895. E. Huth, " Monog. Gattung Delphinium," in Engl. 

 Bot. Jahrb. 20: 322-499, 1895. K. C. Davis, in Bailey's 

 Cyclopedia of American Horticulture. 



SYNOPSIS OF SPECIES OF DELPHINIUM. 



A. Roots annual ; petals only 2, united; follicles i. 



B. Follicles pubescent, y 2 to \y 2 inches long ..i. Ajacis. 



BB. Follicles glabrous, ^ to y 2 inch long 2.consolida. 



A A. Roots perennial ; petals 4; follicles 3 to 5. 

 B. Sepals red. 



C. Plant glabrous ; seeds smooth 3. nudicaule. 



CC. Plant partly pubescent ; seeds thin winged 4. cardinale. 



BB. Sepals greenish yellow, yellow, or sometimes marked with 

 blue. 

 C. Inflorescence and leaves densely hairy. 



D. Flowers not tinged with blue 5. viridescens. 



DD. Flowers sordid white tinged with blue... 6. Calif ornicum. 

 CC. Inflorescence and leaves glabrescent or soon becoming so. 



D. Mature follicles densely hairy 7. Przeivalskii. 



DD. Mature follicles smooth or sulcate. 



E. Seeds with plates or scales in transverse rows... 8. Zalil. 



EE. Seeds winged and somewhat wrinkled... 9. viride. 



BBB. Sepals blue, or varying to white, or white. 



C. Species native north of Mexico, or introduced from Old 

 World. 

 D. Height \y 2 feet or less. 



E. Natives of America north of Mexico. 



F. Petioles dilating and somewhat sheathing at the base. 

 G. Stem lax ; follicles glabrous or becoming so. 



H. Roots fascicled and thickened but not tuberiform. 



10. bicolor. 

 HH. Roots fasciculately tuberous, or grumose. 



n. decorum. 



GG. Stem rather stout, erect : follicles pubescent. 

 H. Length of sepals about equalling the petals. 



I. Seeds winged at the angles 12. hesperium. 



II. Seeds scaly and bur-like 13. Hanseni. 



HH. Length of sepals much gi-eater than petals. 



14. variegatum. 

 FF. Petioles hardly dilating at the base. 



