Trees of the Northern United States Part 16

Var. _purpurascens_ of this species has flesh-colored or dull-purple flowers, and leaflets quite downy beneath.

[Ill.u.s.tration: ae. macrostachya.]

5. aesculus macrostachya, Mx. (LONG-RACEMED BUCKEYE.) Leaflets 5 to 7, ovate, ac.u.minate, serrate, velvety with hairs beneath. Flowers white, in long, slender, erect cl.u.s.ters; July; petals 4, spreading; stamens very long. A beautiful, widely spreading shrub. 5 to 18 ft. high; from the Southern States; often cultivated. Probably hardy throughout.

GENUS =24. KOELREUTeRIA.=

A small tree with alternate, once to twice irregularly pinnate leaves with many coa.r.s.ely toothed leaflets. Flowers conspicuous, yellow, in terminal panicles. In summer. Fruit rounded, bladdery, 3-celled, few-seeded pods; ripe in autumn.

[Ill.u.s.tration: K. paniculata.]

=Koelreuteria paniculata=, Laxm. Leaflets thin and very irregularly toothed. Cl.u.s.ters 6 to 12 in. long, of many irregular flowers, in.

wide; through the summer. Fruit an ovate, bladdery capsule, ripening in autumn. A fine, small, round-headed tree, 20 to 40 ft. high; from China.

Probably hardy throughout.

GENUS =25. aCER.=

Trees, or rarely shrubs, with simple, opposite, and almost always palmately lobed leaves, which, in our species, are always deciduous.

Flowers small and usually dull-colored, in cl.u.s.ters. Fruit double-winged and 2-seeded, in some species hanging on the tree till the leaves have fallen; in others dropping off early in the spring. The species differ much in the spreading of the wings of the fruit. Wood light-colored and medium hard; bark rather smoothish, but in large trees with longitudinal cracks.

* Leaves slightly or not lobed 13.

* Leaves about 3-lobed (rarely 5-lobed); shrubs or small trees.

(=A.=)

=A.= Leaves serrate 1, 2.

=A.= Leaves somewhat sinuate, not at all serrate; juice milky. 10.

* Leaves 5-, rarely 3-lobed. (=B.=)

=B.= The lobes acute, irregularly but quite fully serrate; juice not milky. (=C.=)

=C.= The fruit in corymbs, dropping early; American species. (=D.=)

=D.= Leaf-notches somewhat rounded; tree large; limbs drooping on old trees 3.

=D.= Leaf-notches acute; tree small 4.

=C.= Fruit in hanging racemes, remaining on the tree till autumn; leaves thickish 5.

=B.= The lobes acute; sparingly or not at all serrate. (=E.=)

=E.= Juice not milky 6.

=E.= Juice milky at the bases of the leaves 8, 9.

=B.= The lobes obtuse and sinuate 10.

* Leaves 5- to 7-lobed. (=F.=)

=F.= Lobes fully serrate 11.

=F.= Lobes sparingly serrate. (=G.=)

=G.= Juice milky 8, 9.

=G.= Juice not milky; leaves 8 to 10 in. broad 7.

=F.= Lobes somewhat sinuate, not serrate; juice milky 10.

* Leaves with 7 or more lobes 11, 12.

[Ill.u.s.tration: a. spicatum.]

1. =acer spicatum=, Lam. (MOUNTAIN MAPLE.) Leaves with 3 (rarely 5) coa.r.s.ely serrated, taper-pointed lobes, with slightly cordate base; downy beneath. Flowers greenish-yellow, in erect, slender racemes or panicles, blooming in June. Wings of the small fruit at about a right angle. Small tree, 6 to 10 ft. high, or usually a shrub, with brown twigs. Native; growing in moist woods; rarely cultivated.

[Ill.u.s.tration: a. Pennsylvanic.u.m.]

2. =acer Pennsylvanic.u.m=, L. (STRIPED MAPLE.) Leaves large, thin, 3-lobed at the end, cordate at base, finely and sharply doubly serrate.

Flowers greenish, in drooping, elongated, loose racemes appearing after the leaves in spring. Fruit with large diverging wings. A small, slender tree, with light green bark striped with dark red. Wild throughout and cultivated.

[Ill.u.s.tration: a. dasycarpum.]

3. =acer dasycarpum=, Ehrh. (SILVER OR WHITE MAPLE.) Leaves large, truncated at base, 5-lobed, with blunt notches, the lobes irregularly serrated and notched, silvery white, and, when young, downy beneath.

Flowers light yellowish-purple, preceding the leaves, in crowded umbels along the branches. Wings of fruit large and forming about a right angle; ripe early in June. A rather large, rapidly growing, and usually somewhat weeping tree, with soft white wood. Special cut-leaved and weeping varieties are sold at the nurseries. Wild along river-banks, and extensively cultivated in the streets of cities.

[Ill.u.s.tration: a. rubrum.]

4. =acer rubrum=, L. (RED MAPLE.) Leaves cordate at base and cleft into 3 to 5 acute-notched, irregularly toothed lobes, whitish beneath, turning a bright crimson in early autumn. Flowers usually scarlet, rarely yellowish, in close cl.u.s.ters along the branches, appearing before the leaves in the spring. Fruit often reddish, small, with the wings at about a right angle. A rather small, somewhat spreading tree with reddish branches; wild in wet places and often cultivated.

[Ill.u.s.tration: a. Pseudoplata.n.u.s.]

5. =acer Pseudoplata.n.u.s=, L. (SYCAMORE-MAPLE.) Leaves thickish, cordate, downy beneath, with 5 rather crenately toothed lobes, on long, often reddish petioles. Flowers in long pendulous racemes, appearing after the leaves. Fruit hanging on the tree till after the leaves fall in the autumn, the wings forming about a right angle. A rather large, spreading tree, 30 to 80 ft. high, with reddish-brown twigs. Cultivated; from Europe. Many varieties of this species are sold by the nurserymen; among them may be mentioned the Purple-leaved, Golden-leaved, Silver-leaved, Tricolored, etc.

[Ill.u.s.tration: a. saccharnum.]

6. =acer saccharnum=, w.a.n.g. (SUGAR OR ROCK MAPLE.) Leaves deeply 3- to 5-lobed, with rounded notches; lobes acute, few-toothed; base heart-shaped, smooth above, glaucous beneath. Flowers hanging in umbel-like cl.u.s.ters at the time the leaves are expanding in the spring.

Fruit with wings not quite forming a right angle. A large (50 to 100 ft.

high), very symmetrical tree, ovate in form, with whitish-brown twigs.

Wild throughout, and extensively cultivated in the streets of cities.

Var. _nigrum_, Torr. and Gray. (Black Sugar-maple.) Leaves scarcely paler beneath, but often minutely downy; lobes wider, often shorter and entire; notch at the base often closed (the under leaf in the figure).

Found with the other Sugar-maple, and quite variable.

[Ill.u.s.tration: a. macrophllum.]