Identifying characteristics:
American plum is a common shrub or small tree 10 to 30 feet tall, often
forming colonies along roadsides in its native region. It is a fast-growing,
short-lived species, with a broad, rounded crown and rigid branches with
thorn-tipped dwarf shoots. The 2- to 4-inch-long leaves
are simple, alternate and sharply doubly-serrate along the margins. The
upper leaf surface is dark green and smooth; the lower paler and slightly
downy. Leaf stalks are often downy, with or without glands. Showy, white,
fragrant flowers are produced with
or before the leaves in spring. Flowers occur in clusters of 2 to 5, each
1 inch in diameter, with 5 rounded petals, 15 to 20 stamens and 1 style.
The fruit is a drupe, 1 inch in diameter,
produced singly or in clusters of 2 to 4. Fruits ripen in late August and
are red or purplish, with a tough, astringent skin and juicy, yellow, edible
flesh enclosing a large, flattened pit. Buds are ovoid and sharp-pointed,
with smooth, reddish-brown scales. Terminal buds are absent. Bark is thin, reddish-brown and smooth, breaking
into thin, scaly plates with age.
Similar species: Native cherries (Prunus sp.) such as
Ecology:
Distribution: American plum is native to eastern and midwestern North
America, extending locally in the west. It is native throughout Iowa.
Habitat: This species is found along fencerows, wood edges and streams. It prefers rich, deep, moist soils and is commonly found in bottomlands. It is tolerant of drought and various soil conditions. It is less susceptible to pests and diseases than many other spring-flowering trees, but black knot and tent caterpillar may occur.
Uses:
Wood: The reddish-brown wood is strong, hard and moderately
heavy but trees are too small to make this a commercially viable timber
species.
Wildlife: This is an important native species for wildlife, but not for its fruit. Although the fruits are reportedly consumed by foxes, they are not particularly favored by birds. The American plum was mentioned in De Soto's 1539 writings, where he mentioned the fruits as being part of the Native American diet. Fruits may be used in jellies, preserves and pies. Wildlife make extensive use of the dense, thorny growth habit for cover and nesting sites. Many edible plum varieties have been developed from this species, and it is often used as understock for grafted commercial varieties.
Horticulture: American plum is cultivated for its edible fruit and attractive flowers, and is planted in parks and orchards. It is used for windbreaks, wildlife plantings and erosion control because it requires no special maintenance, is fast-growing and drought-resistant.
