Page  111 ï~~2005 THE MICHIGAN BOTANIST 111 THE BIG TREES AND SHRUBS OF MICHIGAN 47. Acer negundo L. Box Elder or Ash-leaf Maple Elwood B. Ehrle Department of Biological Sciences Western Michigan University Kalamazoo, MI 49008 woodyehrle5098@sbcglobal.net The largest known Box Elder in Michigan is located in Milan, MI, in Washtenaw County in the southeast portion of Michigan's Lower Peninsula. This is a State and National Co-Champion tree. Description of the species: The Box Elder is the only maple in Michigan having pinnately compound, opposite leaves and the characteristic maple samara fruit (Fig. 1). Box Elders have trunks that frequently branch close to the ground. The twigs are green and have a waxy bloom. The Box Elder flowers in late April or early May just as the leaves are becoming obvious. The trees are dioecious. The samaras are quite distinctive. They are "narrow, flat and in v-shaped pairs" (Barnes & Wagner, 1981). Location of Michigan's Big Tree: Milan, MI, is south of Ann Arbor and can be reached by taking exit 180 (Rt. 23 S ) off 1-94 and heading south to Carpenter St. (exit 27). Carpenter St. becomes Dexter St. in Milan. Continue south on Dexter St. to the end and turn left onto Main St. The tree is beside the driveway at 226 Main St., next to a white house with blue trim and a large porch. The coordinates for this location are 42Â~ 04.970' N and 83Â~ 40.710' W. Description of Michigan's Big Tree: The tree has a healthy, solid, single trunk to a height of 5'. It then divides into three large branches. The girth was measured at 260" on 23 August 2003 by Gail McPherson of Global ReLeaf of Michigan, Richard Pomorski, noted Ann Arbor area Big Tree hunter, and Elwood B. Ehrle. The height was 76' and the average crown spread 67'. The total number of points for this tree (Girth + Height + % of the crown spread) is, therefore, 260 + 76 + of 67 = 353. There is another very large Box Elder near Milan, MI. It is the former State and National Champion tree. It can be found at Saline and Mooresville Roads northwest of Milan. It was measured at G = 214, H = 110, & C.S. = 127. The total points for this tree (G + H + Y of C.S.) = 356. These two trees are Co-champions in several ways The tree at Dexter and Main Sts. has a larger girth, but the tree at Saline and Mooresville Rds. is higher and has a wider crown.

Page  112 ï~~112 THE MICHIGAN BOTANIST Vol. 44 7 3 6 FIGURE 1. Documented distribution and characteristics of the Box Elder. The map is from Voss (1985). The asterisk shows the location of the State and National Co-Champion trees. The illustration is from Barnes and Wagner (1981). 1. Winter twig, xl. 2. Leaf, x %. 3. Male flowering shoot, x%. 4. Male flower, enlarged. 5. Female flowering shoot, x%. 6. Female flower, enlarged. 7. Fruit, samara, xl. INVITATION TO PARTICIPATE If you would like to join in extending this series of articles by visiting and describing one or more of Michigan's Big Trees, please contact Elwood B. Ehrle (woodyehrle5098 @ sbcglobal.net) for help with locations, specifications for taking measurements, and assistance with the manuscript. The Michigan Botanical Club encourages your involvement with this activity. Please remember to ask permission before entering private property. LITERATURE CITED Barnes, B. V. & W. H. Wagner, Jr. 1981. Michigan Trees: A Guide to the Trees of Michigan and the Great Lakes Region. University of Michigan Press, Ann Arbor, MI. viii + 383 pp. Voss, E. G. 1985. Michigan Flora, Part II. Dicots (Saururaceae - Cornaceae). Bulletin of the Cranbrook Institute of Science #59 and University of Michigan Herbarium. xiv + 487 pp.