Nettle-tree, _Celtis occidentalis._(A)

Katsura-tree, _Cercidiphyllum j.a.ponic.u.m._(DD) A small or medium-sized tree of very attractive foliage and habit.

Red-bud, or Judas-tree, _Cercis Canadensis._(A) Produces a profusion of rose-purple pea-like flowers before the leaves appear; foliage also attractive.

Yellow-wood, or virgilia, _Cladrastis tinctoria._(A) One of the finest hardy flowering trees.

Beech, _f.a.gus ferruginea._(A)(D) Specimens which are symmetrically developed are among our best lawn trees; picturesque in winter.

European beech, _F. sylvatica._(D) Many cultural forms, the purple-leaved being everywhere known. There are excellent tricolored varieties and weeping forms.

Black ash, _Fraxinus nigra_ (_F. sambucifolia_).(A)(D) One of the best of the light-leaved trees; does well on dry soils, although native to swamps; not appreciated.

White ash, _F. Americana._(A)(D)

European ash, _F. excelsior._(D) There is a good weeping form of this.

Maiden-hair tree, _Ginkgo biloba_ (_Salisburia adiantifolia_).(DD) Very odd and striking; to be used for single specimens or avenues.

Honey locust, _Gleditschia triacanthos._(A)(D) Tree of striking habit, with big branching thorns and very large pods; there is also a thornless form.

Kentucky coffee-tree, _Gymnocladus Canadensis._(A) Light and graceful; unique in winter.

Bitternut, _Hicoria minima_ (or _Carya amara_).(A) Much like black ash in aspect; not appreciated.

Hickory, _Hicoria ovata_ (or _Carya_) (A)(D)(DD) and others.

Pecan, _H. Pecan._(A)(D) Hardy in places as far north as New Jersey, and reported still farther.

b.u.t.ternut, _Juglans cinerea._(A)

Walnut, _J. nigra._(A)

Varnish-tree, _Koelreuteria paniculata._ A medium-sized tree of good character, producing a profusion of golden-yellow flowers in July; should be better known.

European larch, _Larix decidua (L. Europoea_).(DD)

American larch or tamarack, _L. Americana._(A)

Gum-tree, sweet gum, _Liquidambar styraciflua._(A)(D) A good tree, reaching as far north as Connecticut, and hardy in parts of western New York although not growing large; foliage maple-like; a characteristic tree of the South.

Tulip tree or whitewood, _Liriodendron Tulipifera._(A)(D) Unique in foliage and flower and deserving to be more planted.

Cuc.u.mber tree, _Magnolia ac.u.minata._(A)(D) Native in the Northern states; excellent.

White bay-tree, _M. glauca._(A)(D) Very attractive small tree, native along the coast to Ma.s.sachusetts; where not hardy, the young growth each year is good.

Of the foreign magnolias hardy in the North, two species and one group of hybrids are prominent: _M. stellata_ (or _M. Halleana_) and _M.

Yulan_ (or _M. conspicua),_ both white-flowered, the former very early and having 9-18 petals and the latter (which is a larger tree) having 6-9 petals; _M. Soulangeana,_ a hybrid group including the forms known as _Lennei, nigra, Norbertiana, speciosa, grandis._ All these magnolias are deciduous and bloom before the leaves appear.

Mulberry, _Morus rubra._(A)

White mulberry, _M. alba._

Russian mulberry, _M. alba_ var. _Tatarica._ Teas' weeping mulberry is a form of the Russian.

Pepperidge or gum-tree, _Nyssa sylvatica_(A) One of the oddest and most picturesque of our native trees; especially attractive in winter; foliage brilliant red in autumn; most suitable for low lands.

Iron-wood, hop hornbeam, _Ostrya Virginica._(A) A good small tree, with hop-like fruits.

Sourwood, sorrel-tree, _Oxydendrum arboreum._(A) Interesting small tree native from Pennsylvania in the high land south, and should be reliable where it grows wild.

Plane or b.u.t.tonwood, _Plata.n.u.s occidentalis_(A)(D)(DD) Young or middle-aged trees are soft and pleasant in aspect, but they soon become thin and ragged below; unique in winter.

European plane-tree, _P. orientalis._(D) Much used for street planting, but less picturesque than the American; several forms.

Aspen, _Populus tremuloides,_(A) Very valuable when well grown; too much neglected (Fig. 33). Most of the poplars are suitable for pleasure grounds, and as nurses for slower growing and more emphatic trees.

Large-toothed aspen, _P. grandidentata._(A) Unique in summer color; heavier in aspect than the above; old trees become ragged.

Weeping poplar, _P. grandidentata,_ var. _pendula._ An odd, small tree, suitable for small places, but, like all weeping trees, likely to be planted too freely.

Cottonwood, _P. deltoides_ (_P. monilifera_).(A) The staminate specimens, only, should be planted if possible, as the cotton of the seed-pods is disagreeable when carried by winds; var. _aurea_(DD) is one of the good golden-leaved trees.

Balm of Gilead, _P. balsamifera_(A) and var. _candicans._(A) Desirable for remote groups or belts. Foliage not pleasant in color.

Lombardy poplar, _P. nigra,_ var. _Italica._

Desirable for certain purposes, but used too indiscriminately, it is likely to be short-lived in northern climates.

White poplar, abele, _P. alba._

Sprouts badly; several forms.

Bolle's poplar, _P. alba,_ var. _Bolleana._

Habit much like the Lombardy; leaves curiously lobed, very white beneath, making a pleasant contrast.

Certinensis poplar, _P. laurifolia_ (_P. Certinensis_).

A very hardy Siberian species, much like _P. deltoides,_ useful for severe climates.

Wild black cherry, _Prunus serotina._(A)

European bird cherry, _Prunus Padus._

A small tree much like the choke cherry, but a freer grower, with larger flowers, and racemes which appear about a week later.

Choke cherry, _P. Virginiana._(A)