1915] 



GREENMAN MONOGRAPH OF SENECIO 615 



and persistent floccose tomentum along the rhachis or midrib 



26. S. coahuilensis Greenm. Monogr. Senecio, I. Teil, 23. 

 1901, and in Engl. Bot. Jahrb. 32 : 19. 1902 ; Field Col. Mus 

 Bot. Ser. 2 : 275. 1907. 



Plate 19, fig 



An herbaceous perennial, glabrous or essentially so through- 

 out ; stem erect, 3 to 8 dm. high, branched, striate ; leaves pin- 

 nately divided into obovate to subreniform cuneate-dentate 

 divisions, thickish and firm in texture, glabrous on both sur- 

 faces or slightly pubescent on the veins beneath ; lower leaves 

 including the petiole 1 to 3 dm. long, 2 to 5 cm. broad, the 

 upper stem-leaves sessile and amplexicaul ; inflorescence ter- 

 minating the stem and branches in a compound corymbose 

 cyme ; heads 7 to 10 mm. high, radiate ; involucre campanulate, 

 calyculate with a few small bracteoles, glabrous; bracts of 

 the involucre 13 to 18, linear-lanceolate, 4 to 6 mm. long, thick- 

 ish ; ray-flowers 8 to 10, rays oblong, 3 to 5 mm. long, 4-nerved ; 

 disk-flowers 35 to 45; achenes ribbed, glabrous. 



Distribution : northern Mexico. 



Coahuila: Lerios, Feb. to Oct., 1880, Palmer 755 (Gray 

 Herb., Kew Herb., and U. S. Nat. Herb.), type; without local- 

 ity, coll. of 1848-49, Gregg 403 (Gray Herb, and Mo. Bot. 

 Gard. Herb.). 



27. S. leonensis Greemn. Monogr. Senecio, I. Teil, 23. 

 1901, and in Engl. Bot. Jahrb. 32 : 19. 1902 ; Field Col. Mus. 

 Bot. Ser. 2 : 276. 1907. Plate 19, fig. 1. 



An herbaceous perennial, more or less lanate-tomentose 

 throughout, somewhat glabrate in age ; stem 2 to 3 dm. high, 

 leafy at the base, essentially naked above; leaves petiolate, 

 pinnately divided, including the petiole 8 to 12 cm. long, about 

 3 cm. broad, at first lanate-tomentulose on both surfaces, 

 later glabrate ; divisions of the leaf rather coarsely, somewhat 

 unequally and sharply dentate, the terminal segment subren- 

 iform, the lateral ones (3 to 6 on either side) obovate-cuneate ; 

 heads few, about 1 cm. high, radiate; involucre campanulate, 

 slightly calyculate and, as well as the bracteate peduncle, 

 tomentulose; bracts of the involucre about 13; disk-flowers 

 numerous, 50 to 60; achenes pubescent. 



