fVor.. 2 



576 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



Nat. Pflanzenf. IV. Abt. 5, 296. 1892, excl. Emilia; Greenm. 

 Monogr. Senecio, I. Teil, 1901, and in Engl. Bot. Jahrb. 32 : 

 1-33. 1902 ; Dalla Torre & Harms, Gen. Siph. 563. 1900-1907, 



mainly. 



Jacobaea Thunb. Fl. Cap. Prodr. Praef. 1794. 



Obaejaca Cass. Diet. Sci. Nat. 35 : 270. 1825. 



Roldana LaLlave & Lex. Nov. Veg., fasc. 2, 13. 1825. 



Rugelia Schuttlew. in Cliapm. Fl. Southern U. S. 246. 1860. 



C acedia, Cineraria, and Gynoxis, in part, of authors. 



Heads heterogamous and radiate, or discoid. Involucre 

 cylindrical campanulate, occasionally flask-shaped, usually 

 subtended by calyculate bracteoles; bracts of the involucre 

 uniseriate, or by overlapping subbiseriate, variable in number 

 but tending to approach a definite series of numbers, namely 

 5_8-13-21. Ray-flowers when present disposed in a single 

 row, fertile; rays sometimes more or less reduced. Disk- 

 flowers perfect; corollas slenderly tubular to abruptly am- 

 pliated above into a campanulate 5-toothed limb, teeth mostly 

 short. Anthers obtuse or slightly sagittate at the base. 

 Style-branches subterete, recurved-spreading, truncate, 

 rounded-obtuse, occasionally terminated by a small penicillate 

 tuft of hairs, or (in the subgenus Pseudo gynoxis) terminated 

 by a triangular acute or acuminate appendage. Achenes sub- 

 terete, usually ribbed, glabrous, or more or less hirtellous 

 especially on the ribs. Pappus of numerous usually white 

 se tae.— Annual, biennial, or perennial herbs, shrubs, climbers, 

 or even arboreous plants, with alternate or radical, very 

 variable, pinnately or palmately veined, entire or variously 

 divided leaves. 



Synopsis of the Subgenera and Sections 

 Subgenus I. Eusenecio Hoffm. Style-branches truncate, 

 rounded-obtuse or occasionally terminated by a penicillate 

 tuft of hairs. 



A. Stems erect or ascending, not climbing. 



a. Stems not abruptly terminated by a fore- 

 shortening of the main axis; oil-tubes not richly 

 developed in the peripheral portion of the. stem. 

 a. Leaves pinnately veined; lateral nerves not 

 numerous or conspicuous. 

 I. Annual herbs § 1- Aiuint 



