22 ILLINOIS NATURAL HISTORY SURVEY MANUAL 3 



16. Leaflets 5 or 7 per leaf Aesculus, p. 175 



16. Leaflets 3 per leaf Staphylea, p. 173 



15. Leaflets many, pinnately arranged. 



17. Climbing vines with aerial roots. Campsis, p. 248 

 17. Erect shrubs Sambucus, p. 252 



12. Leaves alternate, 1 at a node. 

 18. Leaf margins entire. 



19. Leaflets 3 per leaf Ptelea, p. 151 



19. Leaflets usually 5 or more. 



20. Twining vines Wisteria, p. 146 



20. Erect shrubs. 



21. Stems armed with spines . . Zanthoxylum, p. 149 

 21. Stems unarmed. 



22. Leaflets mostly 5 (3 to 7) per leaf 



Potentilla, p. 103 



22. Leaflets 7 or more per leaf. 



23. Leaflets obtuse and mucronate at the 



tip Amorpha, p. 145 



23. Leaflets taper pointed to acuminate.... 



Rhus, p. 153 



18. Leaf margins toothed. 

 24. Leaflets 3 per leaf. 



25. Both leaf surfaces black dotted Ptelea, p. 151 



25. Leaves not black dotted Rhus, p. 153 



24. Leaflets 5 or- more per leaf. 



26. Stems armed with spines or prickles. 



27. Leaves twice compound Aralia, p. 210 



27. Leaves once compound. 



28. Stipules attached to the petioles. . Rosa, p. 117 



28. Stipules free and deciduous Rubus, p. 105 



26. Stems unarmed. 

 29. Vines. 



30. Leaves palmately compound 



Parthenocissus, p. 196 



30. Leaves pinnately compound Ampelopsis, p. 194 

 29. Tall shrubs ; leaves pinnately compound. 



31. A cluster of glands in the rachis channel 



at the base of each leaflet Sorbus, p. 129 



31. No glands on the rachis Rhus, p. 153 



