1006 MISC. PUBLICATION 42 3, U. S. DEPT. OF AGRICULTURE 



S. longilobus, S. spartioides, and perhaps other species, are poison- 

 ous to cattle and horses, less so to sheep, but are seldom eaten when 

 better forage is available. The liver is the organ chiefly affected. 

 S. cruentus DC, of the Canary Islands, is supposed to be the parent 

 of the showy forms cultivated under the name cineraria. 



Key to the species 



1. Leaves pinnatilobate with narrowly linear or linear-filiform entire lobes, or 



entire and narrowly linear or linear-filiform; plants very leafy throughout, 



usually suffrutescent (2). 



2. Leaves entire, narrowly linear, or rarely with a pair of filiform lobes; plant 



essentially glabrous; heads numerous, narrowly campanulate or sub- 



cylindric, in a close cymose panicle 1. S. spartioides. 



2. Leaves pinnatilobate, or the upper ones often entire, or if all the leaves 

 entire (rarely so in S. longilobus), then the plant tomentose (3). 

 3. Heads subcylindric or narrowly campanulate; phyllaries 8 to 10; plant 



glabrous 2. S. multicapitatus. 



3. Heads broadly campanulate; phyllaries 13 to 21; plant glabrous or 

 tomentose (4). 

 4. Bracteoles inconspicuous, less than half as long as the involucre; plant 

 permanently tomentose, or sometimes glabrate below. 



3. S. longilobus. 

 4. Bracteoles conspicuous, half as long as the involucre or longer; plant 



glabrous or nearly so 4. S. monoensis. 



1. Leaves neither pinnatilobate with narrowly linear or linear-filiform entire 

 lobes, nor entire and narrowly linear (5). 

 5. Leaves all or nearly all deeply pinnatifid, with usually toothed or lobed 

 divisions (6). 

 6. Stem uniformly leafy to the inflorescence; leaves laciniately once or twice 

 pinnatifid, the lobes mostly acute or acuminate; heads small and 

 narrow, the involucre 5 to 7 mm. high, 3 to 5 mm. thick. 



5. S. MACDOUGALII. 



6. Stem with the upper leaves generally much reduced; leaf lobes often 



blunt; heads larger, the involucre 6 to 10 mm. high, 4 to 10 mm. 



thick (7). 



7. Plant coarse and tall (70 to 100 cm. high), glabrous and somewhat 



glaucous; leaves with comparatively few divisions, the terminal 



one large, roundish, 2.5 to 5 cm. wide 6. S. quercetorum. 



7. Plant smaller and more slender, not evidently glaucous, often tomentose; 

 leaves mostly with numerous divisions, the terminal one rarely 

 more than 2 cm. wide (8). 

 8. Plant dwarf (10 cm. high or less); heads few; involucre 7 to 10 mm. 



high 7. S. FRANCISCANUS. 



8. Plant taller; heads usually rather numerous; involucre not more 

 than 8 mm. high (9). 

 9. Achenes hirtellous (10). 



10. Phyllaries about 13 8. S. multilobattjs. 



10. Phyllaries about 21 9. S. millelobatus. 



9. Achenes glabrous (11). 



11. Leaves with the primary divisions again pinnatifid into numer- 



ous small divisions 10. S. LYNCEUS. 



11. Leaves not with the primary divisions pinnatifid into numer- 

 ous small divisions (12). 

 12. Plant essentially glabrous except for woolly tufts in the leaf 



axils 11. S. stygius. 



12. Plant more or less tomentose on the leaves and stem. 



12. S. TJINTAHENSIS. 



5. Leaves mostly entire or merely toothed (the stem leaves pinnatifid in S. 

 hartianus, sometimes also in S. neomexicanus) (13). 



13. Heads nodding, discoid 13. S. bigelovii. 



13. Heads not nodding, usually radiate (14). 



14. Leaves suborbicular, about 10 cm. wide, palmately 5- or 7-nerved 

 from the base and conspicuously reticulate, shallowly repand-lobed 

 and repand-dentate; heads very numerous, small, in a broad panicle. 



14. S. seemannii. 



