=f.= Leaves broadly heart-shaped; margin entire; small tree with abundance of red flowers in early spring; fruit a pea-like pod. 32. _Cercis._ =f.= Leaves not as above given. (=g.=) =g.= Leaves broadly heart-shaped, with a serrate margin and a petiole about as long as the blade, sometimes longer; base of leaf not oblique 4. _Idesia._ =g.= Leaves broadly heart-shaped, those on the suckers much lobed; base not oblique; margin serrate; juice milky; bark very tough. (=l.=) =g.= Leaves broadly heart-shaped, with an oblique base; margin regularly serrate; juice not milky 11. _Tilia._ =g.= Leaves slightly if at all heart-shaped at base, usually somewhat oblique, with neither milky juice nor lobes. (=j.=) =g.= Leaves decidedly and quite regularly lobed. (=h.=) =h.= Leaves with 3-5 large lobes, the margin entire or slightly angulated. 10. _Sterculia._ =h.= Leaves star-shaped, with 5-9 pointed, serrate lobes. (=i.=) =h.= Leaves large, irregularly margined; leaf-stem covering the bud; large tree 80. _Platanus._ =h.= Plant quite thorny; fruit berry-like, ending in a conspicuous spreading calyx; small trees or shrubs with apple-like blossoms. 38. _Cratægus._ =h.= Leaves with a tapering base; small tree, almost a shrub, with large Hollyhock-like flowers; plant not thorny 9. _Hibiscus._ =i.= Large tree, with fruit 1 in. in diameter, dry, rough, hanging on a long stem 41. _Liquidambar._ =i.= Small tree with few branches and the trunk usually quite prickly; fruit berry-like in large clusters 44. _Aralia._ =j.= Fruit small berries, with 3 flattened seeds, in clusters in the axils of the leaves, which are decidedly 3-ribbed from the base 21. _Hovenia._ =j.= Fruit small drupes, with 1 seed, either solitary or in pairs in the axils of the leaves. (=k.=) =k.= Plant without prickles; leaves decidedly oblique at base 76. _Celtis._ =k.= Plant with prickles; leaves narrow, decidedly 3-ribbed, and 2-ranked on green twigs 22. _Zizyphus._ =l.= Fruit not very edible; leaves rough above, very hairy below, on some of the twigs opposite 79. _Broussonetia._ =l.= Fruit edible; leaves not very hairy, never opposite 78. _Morus._ =m.= Leaves of 3 entire-edged leaflets; fruit a pea-like pod 28. _Laburnum._ =m.= Leaves of 3 quite regularly serrate, transparent-dotted leaflets 13. _Ptelea._