STANDLEY— TEEES AND SHRUBS OF MEXICO 1575 



Branchlets not white-tomentose at apex. 



Leaves hirsute with subappressed hairs 11. V. erosa. 



Leaves scabrous-hispidulous. 



Leaves opposite essentially throughout, serrate. 



9. V. leptochaeta. 

 Leaves alternate above, coarsely toothed. 



TT 10. V. peninsularis. 



Heads usually numerous, in close cymes or panicles. 

 Heads subcylindric when young. 



Heads 2 to 4; rays about 12 8. V. oligocephala. 



Heads 4 to 10; rays about 2 35. V. luisana. 



Heads campanulate or subglobose. 



Leaves serrate, dentate, or laciniate-lobed, usually densely 



pubescent beneath 33. v. serrata. 



Leaves serrulate, green and sparsely pubescent beneath. 



__ -. 34. V. resinosa. 



rJJtJ. Leaves alternate. 



Leaves very densely and finely silvery-strigillose beneath. 



42. V. hypargyrea. 

 Leaves not silvery-strigillose beneath. 

 Heads larger, in fruit 1 to 1.5 cm. thick. 



Leaves green and essentially glabrous beneath, except for the 



strigose or strigillose costa and veins 43. V. persicifolia. 



Leaves more or less pubescent on the surface as well as the veins 

 beneath. 

 Involucre 7 to 10 mm. high. 



Leaves canescent-tomentose beneath 38. V. robinsonii. 



Leaves green and finely hispidulous beneath. 



10. V. peninsularis. 

 Involucre 6 mm. high or less (rarely higher in V. olivacea) . 

 Fruiting pales with cuspidate, mostly recurved tips. 

 Leaves green and not subtomentose beneath.. 



22. V. liebmannii. 

 Leaves cinerascently subtomentose beneath. 



40. V. cinerascens. 

 Fruiting pales rarely cuspidate, not recurved at tip. 



Leaves sessile, obovate-lanceolate; pales acute; pedicels 



thick and very short 41. V. crassipes. 



Leaves usually petioled, lanceolate to lance-oblong; pales 



acute or obtuse; pedicels mostly slender, not very short. 



Pales and phyllaries obtuse or merely acutish; involucre 



5 to 7.5 mm. high 44. V. olivacea. 



Pales abruptly short-pointed; involucre 3 to 4 mm. high. 



Leaves 1 to 2.5 cm. wide 26. V. oreopola. 



Leaves 3.2 to 6 cm. wide 39. V. chiapensis. 



Heads smaller, in fruit usually 5 to 7 mm. thick. 

 Tips of the pales recurved, at least in fruit. 



Branches glabrous; leaves glabrescent beneath. 



45. V. seemannii. 

 Branches densely hispidulous or pilosulous; leaves rather densely 

 hispidulous or pilosulous beneath. 

 Leaves cinerascently subtomentose-pilosulous beneath. 



40. V. cinerascens. 



