984 CARDUACEAE 



II. AMPLECTENTES. 



Stem 2 dm. or more high, leafy; leaves acute. 



Stem-leaves with clasping bases; stem high, slightly floccose when young. 



4. S. amplectens. 



Stem-leaves not clasping, usually short-petioled. 5. S. pagosanus. 



Stem less than 2 dm. high. 



Rootstock hard, scaly at the top; upper stem-leaves sessile. 6. S. seridophyllus. 

 Rootstock fleshy, not scaly; stem-leaves usually petioled. 

 Basal leaves gradually tapering into the petioles. 



Plant glabrous or nearly so; leaves dentate; bracts oblong. 



7. S. Holmii. 

 Plant arachnoid-floccose; leaves pinnatifid; bracts narrowly lanceolate. 



8. S. taraxacoides. 

 Basal leaves abruptly contracted into the petioles. 9. S. Soldanella. 



III. OCCIDENTALES. 



Plant 2-3 dm. high; stem-leaves obovate or oblong, clasping. 



Plant very leafy; involucres 10-15 mm. broad, short -peduncled or subsessile; achenes 



strigose. 10. S. carthamoides. 



Plant less leafy; involucres about 10 mm. broad, long-peduncled : achenes glabrous. 



11. S. blitoides. 

 Plant about 1 dm. high; stem-leaves spatulate or obovate, scarcely clasping. 



Leaves obovate-spatulate ; plant glabrous; achenes puberulent. 



12. S. Fremontii. 

 Leaves oval, spinulose-dentate; leaf-margins scaberulous ; surfaces with a few hairs; 



achenes glabrous. 13. S. invenustus. 



IV. TRIANGULARES. 



Heads few; involucres 10 mm. high; lower leaf-blades cordate, the upper oval. 



14. S. variifolius. 



Heads usually many ; involucres 6-8 mm. high ; all leaves triangular, or the upper deltoid- 

 lanceolate. 



Stem 3-4 dm. high; leaves fleshy. 15. S. saliens. 



Stem 4-10 dm. high; leaves thin. 16. 5. triangularis. 



V. SERRAE. 



Heads 12-15 mm. high; disk 8-15 mm. broad; whole plant dark green. 



17. S. admirabiUs. 

 Heads 8-10 mm. high; disk 5-6 mm. wide; plant light green. 



Leaves oval-deltoid to lanceolate; panicles elongate. 18. S. Solidago. 



Leaves narrowly lanceolate to almost linear; panicles round-topped. 



Leaves, at least the lower, closely dentate; involucre cylindro-campanulate. 



19. S. serra. 

 Leaves entire; involucres turbinate-campanulate. 20. S. lanceolatus. 



VI. EREMOPHILI. 



Blades of the leaves sinuately lobed, the upper cleft halfway to the midrib. 



Bracts linear-subulate, not thickened on the back. 21. 5. glaucnfolius. 



Bracts linear, carinate on the back. 22. S. Kingii. 



Blades of the leaves pinnatifld or laciniate, cut usually to near the midrib. 

 Leaf-blades ovate in outline; divisions toothed or lobed. 



Involucres 6-7 mm. high, 5-6 mm. broad; bracts black-tipped. 



23. S. ambrosi aides. 



Involucres 7-10 mm. high, 6-8 mm. broad. 24. S. eremopMlus. 



Leaf-blades narrowly oblanceolate ; divisions linear, entire. 25. S. Kuntzei. 



VII. LONGILOBI. 



Plant glabrous, at least in age. 



Leaves except those of the branches pinnately divided. 



Leaves oblanceolate, with lanceolate or oblong lobes or teeth. 



25. S. Kuntzei. 

 Leaves and their divisions linear-filiform. 



Bractlets one-third to one-half as long as the bracts, filiform. 



26. S. filicifolius. 

 Bractlets very short, subulate. 



Involucres campanulate; bracts 12-15. 27. S. Riddellii. 



Involucres almost cylindrical; bracts 8-10. 28. S. muliicapitatus. 



Leaves entire, linear-filiform, or some rarely with a pair of filiform lobes. 



29. S. spartioides. 

 Plant more or less permanently tomentose. 30. S. longilobus. 



VIII. GLAUCESCENTES. 



Basal leaves spatulate or oblanceolate. 



Bracts long-attenuate, slightly if at all black-tipped; lower leaves broadly spatulate. 



31. S. anacletus. 

 Bracts short, acute, with conspicuous black tips. 



Lower leaves broadly spatulate. 32. S. glauccscens. 



Lower leaves oblanceolate. 96. S. lapathifolius. 



Basal leaves narrowly linear-oblanceolate. 33. S. lugens. 



