Page  185 ï~~2005 THE MICHIGAN BOTANIST 185 THE BIG TREES AND SHRUBS OF MICHIGAN 49. Ailanthus altissima (Miller) Swingle Tree-of-Heaven Elwood B. Ehrle Department of Biological Sciences Western Michigan University Kalamazoo, MI 49008 woodyehrle5098@sbcglobal.net The largest known Tree-of-Heaven in Michigan is located in Maryville, MI in St. Clair County in the southeastern portion of Michigan's Lower Peninsula. Description of the Species: The Tree-of-Heaven can be easily recognized by its very large pinnately compound leaves (See Fig. 1), which can be up to three feet long. The leaflets have two or more coarse teeth at their base which are gland-tipped on the underside. Even without leaves, the tree can be easily recognized by its large leaf scars, each of which has nine or more bundle scars arranged in a U-shaped pattern. The Tree-of-Heaven is frequently seen in urban settings. It often grows against buildings and in vacant lots. This tree was celebrated by Betty Smith in her novel, A Tree Grows in Brooklyn. (Elias, 1980). It is a native of China and was introduced to Europe and North America in 1784 (Voss, 1985) as a food plant for silk worms. Location and Description of Michigan's Big Tree: The State Champion Treeof-Heaven is located next to a yellow house at 4003 Electric Ave. near the corner of Sturges Rd. in Maryville, MI. There is another large Tree-of-Heaven on the other side of the house and there are many young seedlings under the tree. Its coordinates are 420 56.291' N x 820 27.263' W. To reach the tree, take Rt. 25 south from downtown Port Huron. It becomes Electric Ave. in Maryville. Follow Electric Ave. to Sturges St. and the tree is near the corner. There is another large Tree-of-Heaven near the corner of Dexter and Phillips St. in Milan, MI, south of Ann Arbor in Washtenaw County, in the southeastern portion of Michigan's Lower Peninsula. This tree can be reached by taking Rt. 23 south from Ann Arbor to Carpenter St. (exit 27). Carpenter St. becomes Dexter St. in Milan, MI. Continue on Dexter St. to Phillips St. The tree is in the front yard of a white house at 745 Dexter St. I measured the girth of the Maryville State Champion tree at 200" on September 4, 2003. Its height was 63' and its average crown spread 76'. The total points (G + H + 1/4 x C.S.) were therefore 200 + 63 + 1/4 x 76 = 282. The trunk has developed a crack with rot inside starting at three feet. The first branch is eight feet from the ground. The Milan tree was measured by Gail McPherson of Global ReLeaf of Michigan, Richard Pomorski, noted Ann Arbor Big Tree hunter, and myself on August 23, 2003. The girth was measured at 180" the height was 55' and the average

Page  186 ï~~186 THE MICHIGAN BOTANIST Vol. 44 186 THE MICHIGAN BOTANIST Vol. 44 FIGURE 1. The documented distribution in Michigan and characteristics of the Tree-of-Heaven. The map is from Voss (1985). The asterisk indicates the location of Michigan's Champion tree. The illustration is from Barnes and Wagner (1981). 1. Winter twig, x 1. 2. Leaf, x 1/8. 3. Leaflet x 1/2. 4. Male inflorescence, x 1/4. 5. Male flower, enlarged. 6. Female flower, enlarged. 7. Fruit, samara, x 1. crown spread 60'. The total points for the Milan tree were 180 + 55 + 1/4 x 60 = 250. The coordinates for the Milan tree are 420 05.481' N x 830 40.605' W. 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

Page  187 ï~~2005 THE MICHIGAN BOTANIST 187 Club encourages your involvement with this activity. Please remember to ask for permission before entering private property. LITERATURE CITED Barnes, B. V. and 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. Elias, T.S. 1980. The Complete Trees of North America. Van Nostrand-Reinhold Co., N.Y. xii + 948 pp. Voss, E.G. 1985. Michigan Flora, Part II Dicots (Saururaceae-Cornacae). Bull. Cranbrook Inst. Sci. 59 and University of Michigan Herbarium. xiv + 487 pp.