STANDLEY TREES AND SHRUBS OF MEXICO. 147 



Bracts peltate or truncate-peltate at the apex. 

 Leaves palmate-nerved. 



Leaves glabrous, equal at the base. 



Leaves 2.5 to 3 cm. w^ide 19. P. lepturum. 



Leaves 14 to 21 cm. wide 20. P. megalophyllum. 



Leaves pubescent, very unequal at the base, about 9 cm. wide. 



21. P. auritupi. 

 Leaves pinnate-nerved. 



Leaves glabrous, 11 to 12 cm. long, 5.5 cm. wide_-22. P. oblongum. 

 Leaves pubescent. 



Leaves conspicuously bullate 25. P. palmeri. 



Leaves not bullate. 



Leaf blades 16 to 25 cm. long, 6 to 12 cm. wide. 



23. P. dilatatum. 

 Leaf blades about 11 cm. long and 5 cm. wide. 



24. P. pseudoasperifolium. 

 Fruit tetragonous. 

 Bracts cucullate, the apex inflexed. 

 Leaves pinnate-nerved. 



Leaf blades broadly elliptic, 21 to 23 cm. long, 11 cm. wide. 



26. P. rohrii. 

 Leaf blades oblong, about 16.5 cm. long and 7 cm. wide. 



27. P. cordovanum. 

 Leaves palmate-nerved. 



Leaves puberulent beneath along the nerves, 20 to 24 cm. long, 14 to 



19 cm. wide, ovate-rounded 28. P. potom.orphe. 



Leaves glabrous, 5.5 to 7.5 cm. long, 2.5 cm. wide, lanceolate to ovate. 



29. P. variifolium. 

 Bracts peltate, truncate-peltate, or truncate at the apex. 



Leaves palmate-nerved, acutish at the base 30. P. berlandieri. 



Leaves pinnate-nerved. 



Central nerve emitting lateral nerves along its whole length. 

 Leaves pubescent beneath, ovate or ovate-oblong. 



31. P. tuberculatum. 

 Leaves glabrous, lance-ovate or lance-oblong. 



32. P. geniculatum. 

 Central nerve emitting lateral nerves for only part its length. 

 Leaves glabrous. 



Petioles about 30 mm. long 33. P. m.elanostictuni. 



Petioles 8 to 10 mm. long 34. P. oaxacanum. 



Leaves pubescent, at least beneath. 

 Petioles mostly 10 to 15 mm. long. 



Leaf blades rounded or cordate at the base. 



Leaves glabrous on the upper surface_35. P. macrophyllum. 

 Leaves pilosulous and scabrous on the upper surface. 



36. P. aduncum. 

 Leaf blades acute or acutish at the base. 

 Leaves glabrous on the upper surface. 



37. P. chamissonis. 

 Leaves scabrous on the upper surface. 



Peduncles hirtellous ; leaves 4 to 7 cm. wide. 



38. P. jalapense. 

 Peduncles glabrous ;' leaves about 8 cm. wide. 



39. P. fischerianum. 



