742 



CONTEIBUTIONS FEOM THE ISTATIONAL HEEBAEIUM. 



>?. triangularis. 



S. crassulus. 

 S. carthamoides. 



Involucre 5 min. high or less; leaves pinnat- 

 ifid almost to the midrib, the segments 



very narrow 19. S. macdougalii. 



Leaves merely toothed or entire. 



Leaves, at least the lower, triangular or tri- 

 angular-cordate; plants usually 1 meter 



liigh or taller 20. 



Leaves not triangular, narrowed at the base; 

 plants lower, seldom more than 30 cm. 

 high. 

 Leaves lanceolate or elliptic, acute, den- 

 ticulate; stems simple 22. 



Leaves obovate or oval, obtuse, coarsely 



salient-dentate; stems branched 21. 



Upper leaves of the stems much. reduced. 



Rootstock very short, never woody; leaves 

 lanceolate, denticulate; stems stout, 40 cm. 



high or less 23. S. lapaihifolius 



Eootstocks elongated, horizontal or ascending, 

 woody; leaves various; stems low or tall. 

 Leaves linear, less than 2 mm. wide; plants 



small, usually less than 15 cm. high 24. S. thurberi. 



Leaves 5 mm. wide or more; plants mostly 

 taller. 



Plants glaucous '. 25. S. lyiicrodontus. 



Plants not glaucous. 

 Plants tall, stout, 50 cm. high or more; 

 heads very numerous; bracts with 



black tips 26. S. atratus. 



Plants lower, slender, mostly less than 50 



cm. high; heads few; bracts not with 



black tips. 



Leaves and stems permanently floccose. 



All leaves pinnatifid, with toothed 



segments 27, 



Leaves merely coarsely toothed, the 



segments entire. 



.28. 



S. fendleri. 

 S. canovirens. 



.29. S. multilobatiLS. 



Leaves and stems finally glabra te. 



Basal leaves pinnatifid 



Basal leaves not pinnatifid. 

 Leaves very thin, yellowish. 



Basal leaves very deeply cordate, 



with a naiTow sinus 30. S. cardamine. 



Basal leaves not deeply or not at 

 all cordate. 



Basal leaves cordate 31. S. pseudaureus. 



Basal leaves not cordate. 

 Basal leaves oblanceolate or 

 elliptic-oblong, attenu- 

 ate at the base, serrate.. 32. 

 Basal leaves oblong or ovate, 

 not attenuate at the 

 base, crenate 33. 



5. quaerens. 

 S.fluvulus. 



