15. — Witchhazel Family. Capsule two-celled, two-beaked. 
Sweet Gum (Liquidambar styraciiiua) . 
Witchhazel ( Hamamelis virginiana) , 
a Parrotia ( P. persica ). 
16— Chinese Rubber Tree Family. No sepals or petals, fruit 
winged, one-seeded. 
a Chinese Rubber Tree ( Eucommia ulmoides) . 
17— Plane Tree Family. Leaf base surrounds bud; flowers in 
spherical head. 
PlaneTree (Ptatanus): American (occidentalis); <? European (a ceri folia). 
18— Apple Family. Ovary inferior, fruit apple-like. 
e Apple ( A/a/us puntila); a Flowering Crab ( A 1. floribunda) . 
e Pear ( Pyrus communis ) . 
Mountain Ash ( Sorbus ): American ( americana); e European (Aucu- 
paria) . 
a Quince ( Cydonia oblonga ). 
Shadbush ( Amelanchier canadensis) . 
Hawthorn ( Crataegus ): Cockspur ( Crusgalli ); e English Hawthorn 
( Oxyacantha); Scarlet Haw (mo/iis). 
19— Plum Family. Ovary superior, stone-fruit. 
Cherry {Primus): Black ( serotina ); Choke ( virginiana ); Pin or Bird 
(pennsylvanica); a Sweet (Avium); a Japanese Flowering C. (ser- 
rulata and Lannesiana); a Sour ( Cerasus ); Wild Plum (. cm eric an a ); 
e Cultivated Plum ( domestica ) a Peach (Persica ) . 
20— Pea Family. Flow r er pea-like, fruit a legume, leaves usually 
compound. 
Redbud ( Cercis canadensis) . 
s Kentucky Coffee Tree (Gyninocladus dioica). 
Honey Locust (Gleditsia Triacanthos) . 
s Yellow-wood or Virgilia ( Cladrastis lutea). 
a Maackia (M. amurensis) . 
Locust (Robinia Pseudacacia ); Clammy Locust (viscosa). 
a Pagoda Tree (Sophora japonica) . 
21— Rue Family. Leaves compound with pellucid glands, ovary 
on disk. 
Hop Tree or Wafer Ash (Ptelea trifoliata) . 
Prickly Ash (Zanthoxylum americanum). 
a Evodia ( E . Danielii). 
a Cork Tree (Phtllodendron am reuse). 
22— Ailanthus Family. Leaves compound with glands, ovary 
on disk. 
a Tree of Heaven (Ailanthus g/andulosa) . 
23 — Mahogany Tree. Leaves compound, ovary on disk, stamens 
united. 
a Cedrela (C. sinensis). 
24 — Sumach Family. Usually shrubs; leaves compound. 
Sumach (Rhus): Smooth (glabra); Velvet or Staghorn (typhina) Dwmrf 
(copallina); Poison ( Vernix); a Varnish Tree (verniciflua ) . 
s American Smoke Tree (Cotinus americanus ) . 
25 — Holly Famii.y. Flowers small, axillary. 
Holly (Ilex): American (opaca); e European (Aquifolium); Moun- 
tain (monticola) . 
26— Maple Family. Leaves opposite, usually palmately lobed, 
fruit winged. 
Maple (Acer): Silver (saccharinnm); Red (rubrvm); Sugar (sac- 
charurn); Boxelder (Negundn); Striped (pennsylranicnm) ;e Norway 
(platanoides); e Sycamore M. (pseudoplatanus); e English Field 
M. ( campestre ); a Japanese (palm alum and japonicum). 
