I ' IMPOSITAE. 



Vol. I i 



3. Senecio viscosus L. Fetid or Viscous Groundsel. 

 Fig. 4612. 



Senecio viscosus L. Sp. PI. 868. 1 753- 



Annual, viscid-pubescent, strong-scented ; stem usually 

 much branched, i-2 high. Leaves 1-2-pinnatifid, 1 4' 3' 

 long, oblong or somewhat spatulate in outline, the segments 

 oblong or cuneate, dentate or incised ; lower leaves peti- 

 oled ; heads few in the corymbs, 3"-4" broad, mostly slen- 

 der-peduncled ; involucre nearly cylindric, 4"-$" high, its 

 bracts linear, acute, with 1-3 shorter outer ones; rays com- 

 monly about 20, very short, recurved and inconspicuous ; 

 achenes glabrous; pappus bright white, about one-third 

 longer than the involucre. 



In waste places and on ballast near the coast, Nova Scotia, 

 New Brunswick and Quebec to North Carolina. July-Sept. 



4. Senecio glabellus Poir. Butterweed. Cress-leaved Groundsel. Fig. 4613. 



. lyratus Michx. Fl. Bor. Am. 2 : 120. 1803. Not L. 1753. 



.S'. glabellus Poir. in Lam. Encycl. 7: 102. 1806. 



Senecio lobatus Pers. Syn. 2: 436. 1807. 



Annual, glabrous throughout, or slightly woolly 

 when young, fleshy and tender; stem hollow, sim- 

 ple or branched, i-3 high. Leaves 2'-io' long, 

 pinnately divided, the segments orbicular, oblong, 

 obovate or cuneate, obtuse, sinuate-dentate, entire or 

 lobed, the terminal segment usually larger than the 

 others; lower and basal leaves slender-petioled ; 

 heads numerous, 7"-io" broad, slender-peduncled 

 in terminal corymbs; involucre nearly cylindric, 25" 

 high, its bracts linear, acute, usually with no small 

 outer ones; rays 6-12; achenes minutely hispidu- 

 lous on some of the angles; pappus white, somewhat 

 longer than the involucre. 



In swamps, North Carolina to Kentucky, Illinois, Mis- 

 souri, Arkansas, Florida, New Mexico and Mexico. 

 April-Sept. 



5. Senecio palustris (L.) Hook. Marsh Fleawort. Pale Ragwort. Marsh 



Groundsel. Fig. 4614 



-sp- SSJS 4 JLXj -5~1, ... j&P Cineraria palustris L. Sp. PI. Ed. 2, 243. 1763. 



Senecio palustris Hook. Fl. Bor. Am. 1 : 334. 1833. 



Annual or biennial, pubescent or glabrate ; stem 

 stout, simple, hollow, 6'-24' high. Leaves lanceo- 

 late, oblong or spatulate, entire, dentate, or lacin- 

 iate, acute or obtuse, z'-'f long, 3"-is" wide, or 

 the upper linear-lanceolate and small, those of 

 the stem sessile and somewhat auriculate-clasping, 

 the basal petioled ; heads numerous, 6" 12" broad, 

 mostly short-peduncled in a large, rather dense, 

 terminal corymb; involucre cylindric, becoming 

 campanulate, 3"-4" high, its bracts linear, acute, 

 more or less pubescent, with no shorter outer 

 ones; rays 15-20 or more, pale-yellow; achenes 

 glabrous; pappus white, elongated, at length twice 

 the length of the involucre. 



In swamps, Iowa and Wisconsin to Manitoba and 

 arctic America, west to Alaska. Reported from Lab- 

 rador. Also in Greenland, northern Europe and Asia. 

 June Aug. 



