Box Elder
Box elders are most common in wet areas, along streams, in wetlands, and along Big Walnut Creek in the Nature Park.
Classsification:
Kingdom: Plantae
Division: Magnoliophyta
Class: Magnoliopsida
Order: Sapindales
Family: Aceraceae (maple family)
Genus species: Acer negundo
Leaves:
Pinnately compound
Usually 3 leaflets per leaf, sometimes 5 or 7 leaflets per leaf
15 cm long, 2.5 to 4 cm wide
Leaflets are coarsely saw-toothed, sometimes lobed
Leaflets are ovate or elliptical, long-pointed at tip, short-pointed at base
Light green and mostly hairless above
Paler and varying in hairiness beneath
Turn yellow (sometimes red) in autumn
Bark:
Light gray-brown
Many narrow ridges and fissures
Becomes deeply furrowed as tree ages
Flowers
Male and female flowers are on separate trees (dioecious)
Flowers emerge before leaves in spring.
Flowers are 5 mm long
Very small yellow-green calyx of 5 lobes or sepals
Several clustered on slender drooping stalks
Male flowers are in corymbs (upright, small, with a branching effect similar to that of an umbrella)
Female flowers are in racemes (long and slender, hanging down).
Fruit:
Seeds are called samaras or keys
Similar in appearance to the paired "helicopter" seeds of maple.
More v-shaped than other maple fruits
2.5 to 4 cm long, pale yellow, 1-seeded.
Mature in summer and remain attached during winter.
Only female trees produce seeds
Habitat:
Wet or moist soils along stream banks and in valleys with various hardwoods; also naturalized in waste places and roadsides.
Range:
Southern Alberta east to extreme southern Ontario and New York, south to central Florida, and west to southern Texas; also scattered from New Mexico to California and naturalized in New England.
Common Uses and Interesting Facts:
Hardy and fast-growing, it is planted for shade and shelterbelts but is short-lived and easily broken in storms.
Plains Indians made sugar from the sap.
Common name indicates resemblance of foliage to elders (Sambucus) and the whitish wood to that Box (Buxus sempervirens).
The box elder bug is about 1/2 inch long and 1/3 as wide. It is black with three red lines on the thorax, a red line along each side, and a red line on each wing. The population of bugs may number into the thousands. Box elder bugs feed on leaves, flowers, and seed pods of Box Elders and Silver Maples.
Sources:
Written by Erin Faulk; edited by Bryan Helm and Vanessa Artman
Photo credits: Vanessa Artman; http://www.uwgb.edu/biodiversity/herbarium/trees/Aceneg01.HTM
www.softcom.net/users/naturenotes/boxelder.htm
Jackson, M.T. 2004. 101 trees of Indiana. Indiana University Press. Bloomington, IN.
Little, E.L. 1998. National Audubon Society field guide to North American trees, eastern region. Knopf Publishers, New York. 714 pages. |
