1915] 



GREENMAN MONOGRAPH OF SENECIO 601 



Monogr. Senecio, I. Teil, 21, 23. 1901, and in Engl. Bot. Jahrb. 

 32 : 17, 19. 1902. 



Biennial or perennial herbs with lyrate or 2-3-pinnatisect 

 leaves and radiate heads. Sp. 14-16. 



Key to the Species 



A. Stem and leaves glabrous or nearly so; invol- 



ucral bracts narrow, about 1 mm. broad; 



bracteoles usually black-tipped 11/. S. rupestris 



B. Stems and leaves more or less permanently 



floecose-tomentulosc; involucral bracts 1.5 to 

 2 mm. broad; bracteoles not black-tipped. 



a. Upper stem leaves once pinnate 15. 8. erueifolius 



b. Upper stem-leaves 2-3-pinnatisect 16. 8. Jucobaea 



14. S. rupestris Waldst. & Kit. Descr. et Ic. PI. Rar. Hung. 



2 : 136. pi. 128. 1805 ; Eeichb. Ic. Crit. 4 : 28. pi. 334. fig. 514. 



1826 ; Strobl, Fl. Admont. 1 : 57. 1881, and in Flora 65 : 478, 



479. 1882 ; von Hayek, Fl. Stierm. 2 : 564. 1913. 



8. laciniatus Bert, in Desv. Jour. Bot. 2 : 76. 1813 ; Amoen. 

 Ital. 102, 408. 1819. 



Senecio nebrodensis var. glabratus DC. Prodr. 6 : 350. 1837. 



Annual or biennial, sometimes becoming perennial, glabrous 

 throughout or slightly pubescent ; stem erect, 3 to 6 dm. high, 

 simple or branched, striate; leaves lanceolate to obovate- 

 lanceolate in general outline, 3 to 10 cm. long, 1 to 4 cm. broad, 

 laciniately lobed or subpinnatiscent, thin in texture, the lobes 

 again sharply dentate ; the lower leaves narrowed into a sub- 

 petiolate base, the upper sessile and semiamplexicaul ; in- 

 florescence a terminal corymbose cyme; heads 8 to 10 mm. 

 high, radiate; involucre calyculate with black-tipped brac- 

 teoles; bracts of the involucre about 21, linear-lanceolate, 

 acute, 6 to 7 mm. long; ray-flowers about 13; disk-flowers 

 numerous; achenes glabrous or slightly hirtellous. 



Distribution: on ballast near Philadelphia. Introduced 

 from Europe. 



Specimen examined: 



Pennsylvania : on ballast, Philadelphia, July, 1880, Martin- 

 dale (Gray Herb.). 



15. S. erueifolius L. Fl. Suecica, ed. 2, 291. 1755; Huds. 

 Fl. Ang. 366. 1798 ; DC. Prodr. 6 : 351. 1837 ; Reichb. Ic. FL 



