78 Phytologia (Aug 2004) 86(2) 



3. Leaves remotely serrulate to nearly entire; vestiture 

 roughly hispid or hispidulous; Jal W. aggregata 



4. Rays white or yellow (6) 



4. Rays red or purplish (5) 



5. Leaves mostly elliptical to oblanceolate, widest 

 above the middle; Gue, Oax, Cps W. purpurea 



5. Leaves mostly lanceolate (to rarely lanceolate- 

 elliptic), widest below the middle; Sin, Dur, Nay W. xylopoda 



6(4). Lower surfaces of leaves minutely appressed- 

 strigose; leaves linear-lanceolate, 5-10 cm long, with only a 

 single well- defined mid- vein; Son, Chi, Sin W. greenmanii 



6. Lower surfaces of leaves variously pubescent, 

 but not as described in the above, the leaves various, 

 3-nervate if linear-lanceolate, then pilose or scabrous 

 beneath with coarse hairs (7) 



7. Leaves spatulate, 1.0-1.5 cm wide; rays white; Nay, 



Jal, Zac W. grayi 



7. Leaves ovate to ovate-lanceolate; rays yellow, 

 salmon-colored or pinkish (white in W. mexicana) (8) 



8. Well-developed leaves on primary branches with blades 

 mostly 35-100 mm long; stems erect or suberect (11) 



8. Well-developed leaves on primary branches 

 with blades mostly 15-30 mm long (9) 



9. Heads aggregate, sessile or nearly so, if solitary then 

 peduncles 1-8 mm long; vicinity of El Tuito, Jal W. talpana 



9. Heads solitary, not aggregate, the peduncles 

 mostly 1 0-40 mm long ( 1 0a) 



