xxxii North American Trees 



12. Winter buds scaly; fruit woody; twigs not spinescent 13 



13. Leaves 3-veined; buds ovoid; fruit globose CELTIS, p. 220. 



13. Leaves many veined; buds minute, subglobose; fruit with con- 

 spicuous knob-like processes PLANER A, p. 221. 



14. Fruit a capsule 15 



14. Fruit a pome or drupaceous 17 



15. Buds small, partially embedded in bark, terminal absent; flowers 

 and fruit in panicles OXYDENDRON, p. 337. 



15. Buds over Yq inch long, not embedded; flowers and fruit in 



aments 16 



16. Buds scaly, terminal present POPULUS, p. 120. 



16. Buds with single cap-like scale, terminal absent 



SALIX, p. 131. 



17. Leaf base heart-shaped; fruit nut-like drupe attached to per- 

 sistent, leafy bract TILIA, p. 319. 



17. Leaf base not heart-shaped; no persistent, leafy bract 18 



18. Fruit fleshy; pith solid 19 



18. Fruit dry; pith chambered 25 



19. Fruit a berry-like multiple; sap milky; terminal bud absent 



MORUS, p. 227. 



19. Fruit single; sap watery; terminal bud present 20 



20. Leaf scars with single bundle trace ; leaves simply toothed . . . 

 ILEX, p. 291. 



20. Leaf scars with 3 bundle traces ; leaves mostly doubly toothed 



21 



21. Fruit a drupe; leaves mostly lanceolate.- PRUNUS, p. 256. 



21. Fruit a pome; leaves mostly oblong to ovate 22 



22. Twigs with sharp thorns CRATAEGUS, p. 253. 



22. Twigs without thorns (often spinescent) 23 



23. Fruit pyriform PYRUS, p. 346. 



23. Fruit globose or nearly so 24 



24. Pome over Vi inch; buds ovoid to globose. .MALUS, p. 244. 



24. Pome under Yz inch; buds acute to acuminate 



AMELANCHIER, p. 251. 



25. Leaves leathery; fruit brown, Yi inch long; crowned with per- 

 sistent calyx SYMPLOCOS, p. 343. 



25. Leaves thin ; fruit nutlike, 2-4 wtnged ; about 2 inches long 



HALESIA, p. 341 . 



