GENERAL KEY TO THE FAMILIES. 



Page. 

 1. Leaves oarrow, needle like. awMibe, or scale-like, usually persistent except in the 



genus Larix, Finaoeae 67 



1. Leaves broad, flat, rarely five times as long as wide, usually deciduous 2 



2. Leaves opposite or whorled, i. e., two or three occur at a node, 3 



2. Leaves alternate, I. e., only one occurs at a node 10 



3. Leaves, or at least most of them, three at a node Bignoniaoeae 211 



3. Leaves always two at a node ■ 4 



4. Leaves simple 6 



4. Leaves compouud 8 



5. Leaves palmately lobed Aceraoeae 190 



5. Leaves not lobed, 6 



6. Leaves serrate. Vibiu-num in Caprifoliaceae "IS 



6. Leaves entire, 7 



7. I^eaves 3-6 inches loner with curving parallel veins; bases of leaf stalks enlarged, 



encircling twigs Cornus in Gornaceae KM 



7. Leaves 18 inches long without curving parallel veins; bases of leaf stalks do not en- 



circle twigs, Chionanthus in Oleaceae 217 



8. Leaves palmately compound Sapindaceae 209 



8. Leaves pinnately compound, 9 



9. Leaflets usually 5-11; finely toothed or entire margined Frazinus in Oleaceae 212 



9. Leaflets usually 3, sometimes 5-lobcd or coarsely serrate, ..Acer Negundo in Aceraceao 197 



ID. Leaves simple 11 



10. Leaves compound 40 



11. lieaves persistent 12 



11. Leaves deciduous 14 



12. Leaves not armed with spiny teeth, 13 



12. Leaves armed with spiny teeth, Ilex opaca in Aquifoliaceae 1S8 



13. Small trees; leaves stout, white silky beneath, not taper pointed; flowers soli- 



tary, Magnolia virginiana in Magnoliaceae 156 



13. Shrubs; leaves leathery, yellowish-green to scurfy beneath, often taper pointed; 



flowers in clusters Rhododendron and Kalmia in Ericaceae 20? 



14. Leaves with entire margins, 16 



14. Leaves with toothed, lobed, or incised margins, 23 



15. Leaves broadly heart-shaped; flowers reddish -purple, shaped like pea blossoms; fruit 



a pea-like pod Cercis in Leguminosae 180 



15. Leaves not broadly heart-shaped; flowers not shaped like pea blossoms; fruit not 



a pea-like pod. 16 



16. Stont axillary spines present; fruit 3-5 inches in diameter, Madura inUrticaceae 153 



16. Stont axillary spines absent; fruit smaller 17 



17. Leaves decidedly aromatic, often somewhat lobed; twigs spicy-aromatic, mucilagin- 



ous if chewed, Lauraceae 161 



17. Leaves not aromatic or lobed; twigs not spicy-aromatic, nor mucilaginous 18 



18. Leaves 2-C inches long; flowers small except pistillate of Diospyros, not soli- 



tary 19 



18. Leaves more than C inches long; flowers large and solitary, 22 



19. Leaves btistle-tipped, linear-lanceolate to oblong; pith star-sbaped; fruit an acorn.... 



Quercus imbricaria and Q,. phellos in Fagaceae 146 

 19. Leaves oval-ovate or obovate, not bristle-tipped ; pith not star-shaped; fruit a drupe 

 or a berry, 20 



