174 Rydberg : Studies on Rocky Mountain Flora 



Plant about 4-6 dm. high, simple. 



Leaves serrate or subentire ; basal leaves I cm. or more, slender- 



petioled. - 9. S. longipetiolatits. 



Stem leaves with long, triangular lobes ; basal leaves 5 cm. or less. 



10. S. fidgens. 

 Basal leaves cuneate, spatulate or broadly oblanceolate, subentire at the base. 

 Lower stem leaves spatulate with a broad-winged petiole ; upper ones 



sessile and with much enlarged bases. 11. S. crocatus. 



Stem leaves neither broad-winged nor with much enlarged bases. 



Basal leaves crenate above the middle. 12. S. cymbalarioides. 



Basal leaves angularly dentate. 13. .V. Jonesii* 



Basal leaves sharply dentate or serrate above the middle. 

 Lower stem leaves cuneate, plant 3-4 dm. high. 



14. S. subcnneatiis. 



Leaves thin. 



Lower stem leaves oblanceolate ; plant about 2 dm. high. 



15. S. acutidens. 



Basal leaves ovate or more commonly cordate, serrate. 16. S. pseudaureus. 

 Basal leaves obovate or oval, crenate or sinuate-dentate. 

 Stem leaves ovate in outline, with broad segments. 



# 17.6*. platylobus. 



Stem leaves lanceolate or oblanceolate in outline, with narrow segments. 



18. S. JIavovirens. 

 Stem leaves spatulate or oblanceolate in outline, with short and broad 



segments. 



19. 6*. aurellus. 



Head discoid. 



First basal leaves reniform. 20. S. nephrophylhis 



None of the leaves reniform. 



Plant stout ; stem leaves with broad laciniate segments. 



Plant slender ; stem leaves with narrow segments. 



21. S, Idahoensis. 



Plant yellowish or light green ; bracts not purple-tinged. 



17. S. Jla vovirens. 

 Plant dark green. 



Basal leaves crenate ; head 8-10 mm. high ; bracts purple-tinged, 



linear. 



22. S. paucifloras. 



Basal leaves wavy ; heads about 6 mm. high ; bracts broadly lanceo- 

 late or oblong, not purple-tinged. 23. S. fedifolius. 



6. Senecio COMPACTUS (A. Gray) Rydb. Mem. Torr. Club, 5 : 



342. 1893 



Senecio aureus var. compactiis A. Gray, Syn. Fl. I 2 : 391. 1884. 

 Dr. Gray's description covers two if not three species. For 



matter of ques- 



ipatu 



tion. I have adopted it for the plant of the plains with a dense 

 cyme and usually pinnatifid-dentate stem leaves. Dr. Gray evi- 

 dently had this plant in mind when he adopted the name com- 



