GENUS 102. 



THISTLE FAMILY. 



6. Senecio spartioides T. & G. Broom-like 

 Senecio. Fig. 4615. 



Senecio spartioides T. & G. Fl. N. A. 2 : 438. 1843. 



Woody at the base, usually branched, sometimes 

 shrubby, glabrous or nearly, so, leafy, i-6 high. 

 Leaves sessile, or the lowest petioled, i'-3' long, 

 linear, entire, or more or less serrate, not lobed; 

 heads corymbose at the ends of the branches, i'-i' 

 broad, slender-peduncled ; involucre cylindric or 

 becoming campanulate, 4"-s" high, its bracts 

 linear, acute or acuminate, usually with some 

 subulate exterior ones; rays 8-15; achenes ca- 

 nescent; pappus bright white. 



Plains, in dry soil, Nebraska to Texas, Wyoming 

 and Arizona. June-Sept. This and the following 

 species were included in the description of the far 

 western 5". Douglasii DC. in our first edition. 



7. Senecio Riddellii T. & G. Riddell's 

 Senecio. Fig. 4616. 



S. Riddellii T. & G. Fl. N. A. 2 : 444. 1843. 

 S. Fremontii (T. & G.) Rydb. ; Britton, Manual 1028. 

 1901. Not JT. Fremontii T. & G. 



Woody at the base, usually branched, some- 

 times shrubby, glabrous or nearly so, leafy, i-6 

 high. Leaves sessile, or the lowest petioled, thick, 

 ii'-3i' long, pinnately parted into 3-9 linear or 

 filiform, entire segments, or the upper entire; 

 heads corymbose at the ends of the branches, 

 5"-io" broad, slender-peduncled ; involucre cylin- 

 dric or becoming campanulate, s"-8" high, its 

 brdcts linear, acute or acuminate, usually with 

 some subulate exterior ones ; rays 8-15 ; achenes 

 canescent ; pappus white. 



Plains, in dry soil, Nebraska to Texas and Mexico. 

 June-Sept. 



Sea-beach 



8. Senecio Pseudo-Arnica Less. 

 Senecio. Fig. 4617. 



I753- Not S. mari- 

 1831. 



Arnica maritima L. Sp. PI. 884. 



timus L. 

 Senecio Pseudo-Arnica Less. Linnaea 6 : 240. 



Perennial, somewhat fleshy; stem stout, mostly 

 simple, very leafy, 6'-3 high. Leaves oblong-obo- 

 vate. lanceolate, or the lower spatulate, acute or 

 obtuse at the apex, 4'-8' long, '-2' wide, densely 

 tomentose beneath, at least when young, repand- 

 dentate or denticulate, narrowed to a sessile and 

 partly clasping base, or the lowest into margined 

 petioles ; heads solitary, or several (2-7) and co- 

 rymbose, stout-peduncled, i*'-2' broad, 8"-io" 

 high ; involucre broadly campanulate, its bracts 

 lanceolate, acuminate, mostly tomentose, common- 

 ly with several subulate spreading ones at the base ; 

 rays 12-25, linear, 3-toothed, conspicuous; disk- 

 corollas 5-lobed; achenes glabrous; pappus dull. 



On sea-beaches and rocks near the sea, Maine, New 

 Brunswick and the lower St. Lawrence to Labrador 

 and the Arctic Sea. Also in Alaska. July-Aug. 



