STANDLEY TREES AND SHRUBS OF MEXICO 1623 



Petioles densely lanate. 



Leaves permanently tomentose on both surfaces. 



T , 27a. S. eriophyllus. 



Leaves tomentose beneath, glabrate above 28. S. lanicaulis 



Heads few, large, 12 to 20 mm. high. 



Leaves angulate-lobed, strongly reticulate-veined. 



Leaves angulately 5-lobed 29. S. reticulatus. 



Leaves 7 to 13-lobed 30. g. acerifolius. 



Leaves subpmnately incised, not strongly reticulate-veined. 



31. S. ehrenbergianus. 

 Inflorescence more or less glandular-hirtellous, often with hirsutish hairs inter- 

 mixed. 

 Leaves 3 to 5-lobed, somewhat halberd -shaped. 



Heads ligulate 32. s. anisophyllus. 



Heads discoid. 



Leaves not peltate. 



Basal lobes of leaf reflexed 33. s. chrismariL 



Basal lobes of leaf horizontally spreading 34. S. hederaefolius. 



Leaves excentrically peltate 35. s. alienus. 



Leaves 5 to 13-lobed, not halberd-shaped. 

 Involucre 5 to 7 mm. high. 

 Ray flowers conspicuous. 



Leaves 5 to 12 cm. broad, 5 to 7-lobed. 

 Leaves sparingly tomentose beneath. 



Leaves angulately 5-lobed 36. S. hederoides. 



Leaves sinuately 7-lobed 37. S. oaxacanus. 



Leaves densely tomentose beneath 38. S. hypomalacus. 



Leaves 20 to 25 cm. broad, 7 to 13-lobed 39. S. langlassei. 



Ray flowers absent 40. S. cristobalensis. 



Ray flowers inconspicuous. 



Upper leaves mostly dentate 41. S. cordovensis. 



Upper leaves mostly entire 42. S. macrobotrys. 



Involucre 8 to 12 mm. high. 



Ray flowers much reduced, inconspicuous. 



Bracts of the inflorescence foliaceous 43. S. angulifolius. 



Bracts of the inflorescence setaceous 44. S. brachyanthus. 



Ray flowers conspicuous. 



Main lobes of the leaf not again angulate-lobed. 



Leaves peltate 45. S. chapalensis. 



Leaves not peltate. 



Peduncles and involucral bracts granulose-hirtellous. 



46. S. sartorii. 



Peduncles and involucral bracts subhirsute 47. S. petasitis. 



Main lobes of the leaf again angulate-lobed. 



Leaf blade about as broad as long 48. S. platanifolius. 



Leaf blade broader than long 49. S. gilgii. 



V. TERMINALES. 

 Leaves pinnately veined. 



Leaves ovate-oblong, rounded to cordate at the base. 



Involucre 10 to 13 mm. high 50. S. orcuttii. 



Involucre 4 to 7 mm. high. 



Leaves thin; pubescence white-floccose 51. S. chicarrensis. 



Leaves thickish; pubescence tawny 52. S. grandifolius. 



