370 The Ohio Naturalist. [Vol. V, No. 8, 



84. Leaves entire or three-lobed, bark spicy-aromatic ; internodes very 

 unequal. Sassafras. 



84. Leaves crenate, serrate, dentate, or lobed, not star-shaped and not 



spicy-aromatic. 85. 



85. Pith 5-angled; trees usually with resinous buds; leaves usually 



broad based. Populus. 



85. Pith cylindrical or nearly so. 86. 



86. With prominent typical thorns; trees or erect shrubs. Crataegus. 



86. Without thorns but often with prickles or bristles; low shrubs. ST. 



87. Leaves lanceolate or ovate-lanceolate with gland-tipped serrations 



or dentations; low erect shrubs. Ceanothus. 



87. Leaves broad and more or less lobed. 88. 



88. Petioles and twigs densely brown-bristly, leaves 4- 8 in. broad, 



angled or lobed. Rubus. 



88. Twigs not bristly, if the petioles are bristly then the leaves much 



smaller. 89. 



89. Bundle scars or vascular bundles in base of petiole widely separate; 



petiole not decurrent at the middle or if so then the petiole with 

 long hairs or distinctly pubescent; plants often prickly; fruit a 

 berry. Ribes. 



89. Bundle scars or vascular bundles in base of petiole closely crowded 



or nearly confluent ; petioles strongly decurrent at the sides and 

 middle; glabrous or only minutely pubescent; plant not pricklj^; 

 fruit a capsule. Opulaster. 



—90— 



90. Leaves glabrous. 91. 



90. Leaves pubescent or woolly at least below. 92. 



91. Leaves 3 i-3^ i"- long, bitter. Oxycoccus. 



91. Leaves 1-2 J^ in. long, acid. Andromeda. 



92. Leaves with a fragrant odor, densely toinentose beneath; erect, 



resinous shrubs. Ledum. 



92. Leaves 2-ranked, small, oval or ovate, hairy; creeping shrubs. 



Chiogenes. 

 —93— 



93. With tendrils; leaves digitate. Parthenocissus. 



93. Without tendrils; leaves trifoliate or pinnate. 94. 



94. Pith diaphragmed, with cavities; large trees with pinnate leaves. 



Juglans. 



94. Pith not diaphragmed. 95. 



95. Leaves trifoliate or odd-pinnate. 96. 



95. Leaves evenly pinnate or bipinnate; axillary buds superposed. 109. 



95. Leaves odd-bipinnate, serrate; twigs and leaves usually ]M-ickly. 



Aralia. 



96. Leaves with spine-tipped teeth, evergreen. Berberis. 



96. Leaves not with spine-tipped teeth; but some may Ije prickly. 97. 



97. Lobes or teeth at the base of the leaflets with prominent green 



glands beneath; leaves pinnate, very large with disagreeable 

 odor. Ailanthus. 



97. Lobes or teeth if present without green glands. 98. 



98. With stipular spines a pair for each leaf; leaflets entire. 99. 



98. Without stipular spines, but some may have thorns or prickles. 100. 



99. Leaflets oval or ovate, not pointed, usually mucronate, not punctate 



Robinia. 

 99. Leaflets ovate, pointed, glandular-punctate. Xanthoxylum. 

 100. Base of petiole covering the axillary Inids; not ])rickly. 101. 



100. Base of petiole not covering the axillary ])uds. 103. 



101. Leaves 3-foliatc, leaflets crenulatc, glandular punctate; bark with 



disagreeable odor; axillary buds superposed. Ptelea. 



