Phytologia (Aug 2004) 86(2) 79 



10a. Ray corollas salmon-colored, pinkish or white; Mex, 



Gue W. hintoniorum 



10a. Ray corollas yellow or yellow-orange; Sin, Dur, 



Nay (10b) 



10b. Rays yellow; leaves widest at or above the middle; 



Oax W. juxtlahuacana 



10b. Rays white; leaves widest above the middle; 



Sin, Dur, Nay W. mexicana 



11(8). Leaves broadly ovate, 1.5-2.5 times as long as wide; 



stems lax or recumbent; Chi W. chihuahuana 



11. Leaves ovate-lanceolate, elliptic-ovate to lanceolate, 



3-8 times as long as wide (12) 



12. Leaves markedly lacerate, the lower surface 



bestowed with few to numerous minute uncinate 



hairs, Chi W. pimana 



12. Leaves remotely serrulate to entire, the lower 



surfaces without uncinate hairs; Sin, Dur, Nay, Jal (13) 



13. Primary leaves lanceolate-ovate to elliptic-ovate, those 

 at mid-stem mostly (6)10-20 mm wide; involucres 

 mostly 8-12 mm high (15) 



13. Primary leaves linear-lanceolate, those at mid-stem mostly 

 3-10 mm wide, the margins enrolled; involucres 

 mostly 6-8 mm high; Dur, Jal (14) 



14. Divaricately branched low shrublets 10-30 cm high; 

 leaves and stems with erect or ascending hairs; 

 s Dur W. gonzaleziarum 



