1. Acer Negúndo Linnæus. Box Elder. [Plate 111.] A medium-sized tree with a short trunk and round head; bark of young trees smooth and gray, becoming thick on old trees, light to dark brown and more or less furrowed or rarely somewhat flaky; twigs smooth and greenish; leaves of average size are 1.5-3 dm. long, generally with 3 leaflets on the flowering branches, sometimes 5 or rarely with 7, on sterile branches or on growing shoots 3-7, the petioles generally 1/3-1/2 the length of the leaf and glabrous or nearly so at maturity; leaflets all on stalks more or less pubescent, the lateral stalks short, the terminal ones much longer, leaflets of varying size and shape, the margins usually varying from lobed to serrate or entire, pinnately veined, smooth above at maturity and remaining more or less pubescent beneath, especially along the veins; flowers appear just before the leaves the last of April or the first of May, the staminate and pistillate on separate trees; fruit matures late in summer, the body of the samara green and more or less pubescent.
Distribution.—New England to Florida, west to Minnesota and south to eastern Texas. In Indiana, it is found throughout the State in moist or wet places along creeks and rivers, and infrequently on the highlands along roadsides and fences. Its original distribution in the State can only be conjectured. Judging from its tolerance to shade and its habitat, and from the earliest reports of its occurrence in the State, this species was quite rare in the northern part of the State, becoming infrequent to frequent in its habitat in the southern part of the State. Even today it is rather local in its distribution. I have never seen it on the low mucky border of a lake.
Remarks.—This species on account of its rapid growth was formerly much used in our area as a shade tree. It is believed that most of the trees now found along roadsides, fences, clearings and on the drier banks of streams are from seed distributed by the wind from planted trees. This species is now little used as a shade tree and is never recommended because it sheds its leaves early, and is subject to injury from disease and insects.
ACER NEGUNDO Linnæus. Box Elder. (× 1/2.)
1a. Acer Negundo variety violàceum Kirchner. (Rulac Nuttallii Nieuwland). This variety is distinguished by its glaucous twigs and by the body of the fruit being glabrous at maturity. In most instances when the bloom is rubbed from the twigs they show a purple tinge, hence the varietal name.
Distribution.—I have this variety in Indiana from the following counties: Brown, Cass, Elkhart, Franklin, Fulton, Hendricks, Henry, Jennings, Lagrange, Martin, Posey, St. Joseph, Vermillion and Wayne.