596 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Akenes glabrous. 



Basal loaves obovate or 

 oblanceolate, dentate 



only toward the apex . . 9. S. cymbalarioides. 

 Basal leaves crenate- 

 dentate from the base 

 to apex or subentire. 

 Glabrous; basal 

 leaves nearly quad- 

 rangular, sinuate, 

 dentate or entire. 10. S. fratemus. 

 ^ More or less pubes- 



cent, especially in 

 the leaf axils; 

 leaves often cune- 



ata at base 8. S. adamsi. 



Leaves not at all pinnate nor pinnatitid. 



Rootsto«k woody; stems low; leaves small, thick 26. S. ductoris. 



Rootsto<"k none or not woody; stems tall; loaves, at 

 least the basal ones, large. 



Stems tall, clustered, leafy to the inflorescence. 

 Leaves triangular-lanceolate, petiolato, 



coarsely dentate 24. S. triangularifi. 



Leaves lanceolate, sessile 



Margin of leaves evenly serrate 25. S. serra. 



Margin of loaves entire 25a. S. serra lanceolatus. 



Stems usually solitary; leaves mostly basal, 

 the cauline much reduced. 

 Herbage wholly glabrous. 



Leaves glaucous, quite fleshy, mostly 



entire 17. S. hydrophilus. 



Leaves not glaucous, mostly dentate. 

 Bracts of the involucre 6 to 7 mm. 



long, stramineous 18. iS. hydrophiloides. 



Bracts of the involucre 7 to 8 mm. 



long, brownish 19. S. foetidus. 



Herbage more or less pul)escent with long 

 jointed somewhat intermixed hairs. 



Heads discoid 20. S. vaseyi. 



Heads radiate. 



Heads 8 to 10 mm high in an- 

 thesis; bracts of the involucre 

 usually 13, from 5 to 7 mm. 



long 21 . S. exaltatus. 



Heads 10 to 12 mm. high in an- 

 thesis; bracts of the involucre 

 about 21, from 6.5 to 8.5 mm. 

 long. 



Inflorescence open 22. S. atriapiculatus 



Inflorescence dense 23. S. condensatus. 



1. Senecio vulgaris L. Sp. PI. 2. 867. 1753. Groundsel. 



Type locality: European. 



Specimens examined: Pullman, Piper, June 2, 1894; Seattle, Piper in 1885; Lower 

 Cascades, Svksdorf, May 29, 1886. 



