acuminate lobes, finely, sharply, and
usually doubly serrate; base heart-shaped, truncate, or rounded;
leafstalks 1-3 inches long, grooved, the enlarged base including the
leaf-buds of the next season.

=Inflorescence.=--In simple, drooping racemes, often 5-6 inches long,
appearing after the leaves in late May or early June; the sterile and
fertile flowers mostly in separate racemes on the same tree; the
bell-shaped flowers on slender pedicels; petals and sepals
greenish-yellow; sepals narrowly oblong, somewhat shorter than the
obovate petals; stamens usually 8, shorter than the petals in the
sterile flower, rudimentary in the fertile, the pistil abortive or none
in the sterile flower, in the fertile terminating in a recurved
stigma.

=Fruit.=--In long, drooping racemes of pale green keys, set at a wide
but not uniform angle; distinguished from the other maples, except _A.
spicatum_, by a small cavity in the side of each key; abundant; ripening
in August.

=Horticultural Value.=--Hardy, under favorable conditions, throughout
New England. Prefers a rich, moist soil near water, in shade; but grows
well in almost any soil when once established, many young plants failing
to start into vigorous growth. Occasionally grown by nurserymen, but
more readily obtainable from northern collectors of native plants.

[Illustration: PLATE LXXVI.--Acer Pennsylvanicum.]

1. Winter buds.
2. Flowering branch.
3. Sterile flower.
4. Fertile flower with part of the perianth removed.
5. Fruiting branch.

=Acer Negundo, L.=

_Negundo aceroides, Moench. Negundo Negundo, Karst._

BOX ELDER. ASH-LEAVED MAPLE.

=Habitat and Range.=--In deep, moist soil; river valleys and borders of
swamps.

Infrequent from eastern Ontario to Lake of the Woods; abundant from
Manitoba westward to the Rocky mountains south of 55 deg. north
latitude.

Maine,--along the St. John and its tributaries, especially in the French
villages, the commonest roadside tree, brought in from the wild state
according to the people there; thoroughly established young trees,
originating from planted specimens, in various parts of the state; New
Hampshire,--occasional along the Connecticut, abundant at Walpole;
extending northward as far as South Charlestown (W. F. Flint _in lit._);
Vermont,--shores of the Winooski river and of Lake Champlain;
Connecticut,--banks of the Housatonic river at New Milford, Cornwall
Bridge, and Lime Rock station.