KEY TO THE GENERA OP TREES 53 



H. Flowers conspicuous, 1 in. or more in size, white. (J.) 

 H. Flowers quite small. (I. ) 



I. Flowers and fruit in large panicles ; leaves elongated, peach- 

 like in shape, sour 50. Oxydendron. 



I. Flowers iu terminal, erect racemes; fruit small, three-celled 

 pods: leaves oval, 3-7 in. long, pointed, thin, finely serrate; 



plant hardly a tree 53. Clethra. 



I. Fruit rounded, small, with calyx adhering to the lower part, 



one-seeded, in clusters of 3-many ; leaves 1-3 in. long 



56. Styrax. 



I. Fruit hairy, in long, hanging panicles, tipped with long, 



persistent style, one-seeded 57. Pterostyrax. 



J. Flowers bell-shaped, 1 in. long ; leaves widest below the mid- 

 dle ; fruit winged pods 58. Halesia. 



J. Flowers spreading, 2 in. broad ; leaves about twice as long as 



wide, widest near the center 7. Stuartia. 



J. Flowers spreading, 3 in. broad ; leaves about 3 times as long as 



wide, widest near tip 8. Gordonia. 



K. Fruit a plum-like drupe with a single bony stone ; plant 



sometimes thorny 36. Prunus. 



K. Fruit berry-like, ending in a conspicuous spreading calyx ; 



plant generally quite thorny 38. Cratsegiis. 



K. Fruit berry-like, black when ripe, small, without calyx, with 



usually 3 cartilaginous coated seeds 20. Bhamnus. 



K. Fruit berry-like, red when ripe, with small calyx at base, and 



usually 4-6 hard-coated, grooved nutlets 18. Hex. 



X. Fruit a small or large apple-like pome, with the seeds in 



horny cells. (L.) 

 L. Fruit about J^ in. in diameter, sweet, in drooping racemes 



'. 39. Amelanchier. 



L. Fruit either sour or much larger, and not in elongated racemes 



37. Pyrus. 



M. Leaves harsh to the touch ; somewhat oblique at base ; quite 



distinctly two-ranked ; large trees 74. Vlmus. 



M. Leaves decidedly oblique at base ; margin wavy ; small tree, 



usually a shrub 40. Hamamelis. 



M. Fruit berry-like, ending in a conspicuous spreading calyx; 



plant generally quite thorny 38. Cratsernis. 



M. Leaves not regularly oblique at base ; plant not thorny. (N.) 

 N. Leaves thin and light, not harsh to the touch; spray light; 

 bark smooth, in two species somewhat rough on the trunk, 

 (ft.) 



N. Leaves thick ; edge wavy, almost lobed ; fruit an acorn 



88. Quercw. 



