Feb., 1905.] Key — Ohio Woody Plants. 279 



24. Shrubs with dehcate sprav-Hke twigs which are self-pruned ; leaves 



minute. TAMARIX. " 



25. With tendrils opposite the leaf scars; usually every third leaf node 



without a tendril; climbing plants self-pruning unripe tAvigs by 

 means of cleavage planes in the leaf nodes. 26. 



25. No tendrils opposite the leaf scars. 27. 



2G. With woody partitions in the brownish pith at the leaf nodes; 

 lenticels inconspicuous; tendrils without adhering disks; surface 

 of leaf scar irregular. VITIS. 



26. Pith continuous, white; lenticels conspicuous; tendrils without 



adhering disks in our species; leaf scar rather smooth. 



AMPELOPSIS. 



26. Pith continuous, white; lenticels conspicuous; tendrils usually with 



adhering disks; leaf scars smooth, concave, with small bundle 

 scars scattered or in a ring. PARTHENOCISSUS. 



— 27 — 



27. Leaf scars alternate. 28. 



27. Leaf scars opposite or whorled. 109. 



28. Twigs with distinct and complete stipular ridges or rings at the leaf 



nodes. 29. 



28. Twigs without complete stipular rings. .31. 



29. Leaf scar surrounding the axillary bud, terminal bud self-pruned; 



wood with prominent medullary rays. PLATANUS. 



29. Leaf scar not surrounding the axillary bud, terminal bud not self- 



pruned ; buds enclosed in the large connate stipules. ,30. 



30. Buds glabrous; twigs brown; pith diaphragmed; leaf scars oval or 



circular; bark spicy- aromatic. LIRIODENDRON. 



30. Buds downy, or if glabrous then the twigs red ; pith with or without 



diaphragms; leaf scars LT-shaped, oval, or circular; bark usually 

 aromatic. MAGNOLLA.. 



31. With thorns, prickles, or spines; or with spur-like branches ending 



in thorns. 32. 



31. AVithovit thorns, prickles or spines but some may have thorn-like 



stunted branches. 42. 



32. With leaves reduced to simple or branches spines. BERBERIS. 

 32. With stipular spines, a pair for each leaf scar. 33. 



32. Twigs with typical lateral thorns, without terminal thorns. 34. 



32. With thorns at the ends of branches or with spur-like branches end- 

 ing in thorns, and in addition axillary thorns may be present. 35. 



32. Stems or twigs with prickles, some of which may have the appear- 

 ance of stipular spines. 39. 



32. Bud scales tipped with spines; stem twining; leaf scar central. 



CELASTRUS. 



33. Leaf scar covering the two or more superposed axillarv buds. 



' ROBINIA. 



33. Leaf scar below the axillary buds; buds reddish, pubescent. 



XANTHOXYLUM, 



34. With thorns beside the axillary buds; normally one for each leaf 



axil, becoming gradually smaller toward the tip of the twig, 

 terminal bud absent. TOXYLON. 

 34. Thorns axillarj-, large, rarely branched except on the main trunk; 

 usually with two lateral buds at the base which may develop as 

 twigs; numerous axils without thorns. CRAT^-EGUS. 



34. Thorns commonly branched, situated above the axil of the leaf; 



leaf scar covering the two or more superposed axillary buds; 

 twigs polished, often zigzag. GLEDITISA. 



35. Not with three distinct bundle scars. 36. 

 35. With three bundle scars. 37. 



