erect, few to several, corymbose; involucres broadly campanulate; phyllaries fleshy 

 thickened on back and near base, blackish-hairy near apex; rays 7-10 mm. long, 

 yellow. 5. semiamplexicaulis Rydb., 5. kipathifoliiis Greene. 



Wet meadows in mts. of N.M. (Rio Arriba Co.), June-Aug.; S.D. to Ida., s. 

 toN.M. and Ut. 



4. Senecio triangularis Hook. 



Perennial or biennial; stems erect, 1 to a few from a heavy horizontal root- 

 stock, 5-20 dm. tall; herbage tomentose when young, usually becoming glabrous; 

 leaves many, gradually reduced upward, lanceolate to triangular-ovate, 5-20 cm. 

 long, cordate, hastate or merely truncate at base, sharply serrate, dentate, denticu- 

 late or nearly entire, the lower leaves on petioles as long as the blade; heads 

 usually many in an open or dense corymbose terminal cyme; involucre 6-8 mm. 

 high; rays 6 to 12, 8-10 mm. long. 



Bogs, marshy areas, and stream margins, in N.M. (Taos, Rio Arriba, San 

 Miguel and Santa Fe cos.), June-Sept.; Alas, and Yuk., s. to Sask., N.M. and 

 Calif. 



5. Senecio pseudaureus Rydb. 



Perennial plant with definite ascending or horizontal rootstocks; stems 3-7 dm. 

 tall, erect, glabrous or tomentose in axils of leaves or in inflorescence; basal leaves 

 1-10 cm. long, ovate-rotund to oblong-ovate, crenate to doubly serrate, usually 

 rounded at apex, some cordate at base, long-petioled; stem leaves more or less 

 lyrate-pinnatifid, short-petioled or sessile and clasping, reduced upwards, glabrous 

 or glabrate; heads 8-10 mm. high, erect, few to many in a corymbose cyme; 

 involucre campanulate, calyculate; phyllaries about 21, rarely as few as 13, 6-8 

 mm. long, glabrous except at apex; rays yellow, 10 to 13, 6-9 mm. long; achenes 

 glabrous. 



Wet meadows and wet stream banks, N. M. (Rio Arriba Co.), June-Aug.; Sask. 

 to B.C., s. to N.M. and Calif. 



6. Senecio pauperculus Michx. 



Fibrous-rooted perennial with a rather short simple or slightly branched caudex, 

 occasionally with some very short slender stolons, 1-5 dm. high, lightly floccose- 

 tomentose when young, glabrescent except at the very base and in the leaf axils; 

 basal leaves petiolate, the blade oblanceoJate to elliptic or occasionally suborbi- 

 cular, crenate or serrate to subentire; cauline leaves more or less pinnatifid, the 

 lower sometimes larger than the basal, the others conspicuously reduced and 

 becoming sessile, all relatively thin and not at all succulent; heads several, the 

 disk 5-12 mm. wide; involucre mostly 6-9 mm. high; rays mostly 5-10 mm. long, 

 or rarely wanting. S. ftavovirens Rydb. 



Swamps, meadows, stream banks in N.M. (San Miguel, Rio Arriba, Socorro and 

 Sierra cos.), May-Oct.; Lab. to Va., w. to s. Yuk., B.C., Ore. and N.M. 



7. Senecio salignus DC. 



Woody, moderately branched shrub to 2.5 m. tall, glabrous throughout; bark 

 reddish-brown on younger branches, tawny to gray on old growth, youngest twigs 

 green and finely striate; leaves narrowly lanceolate or narrowly elliptic, to 1 dm. 

 long, 5-10 mm. wide, tapering gradually toward each end, usually serrate, the 

 teeth somewhat callous-tipped, dark green on upper surface, paler beneath; petioles 

 gradually merging with blade; inflorescence corymbose, cymes to 1 dm. wide; heads 

 radiate, 10-12 mm. high; involucres campanulate, phyllaries 7 to 9, broadly oblong 

 or oblanceolate, 5-6 mm. long, 2-2.8 mm. wide, obtuse or rounded at the tip, 

 somewhat hardened at the base, thin, with the margins scarious; ray flowers 2 to 



8. sometimes wanting, ligules pale-yellow, 5-7 mm. long, about 2 mm. wide, 



1691 



