Page  51 ï~~2000 THE MICHIGAN BOTANIST 51 THE BIG TREES OF MICHIGAN 26. Acer pseudo-platanus L. Sycamore Maple Bonnie B. Harnish, Chair Elwood B. Ehrle Lake Bluff Audubon Center Department of Biological Sciences Manistee, MI 49960 Western Michigan University Kalamazoo, MI 49008 Michigan's largest known Sycamore Maple stands on the grounds of the Lake Bluff Audubon Center near Manistee, Manistee County, MI, on the western side of the lower peninsula. Description of the Species: The Sycamore Maple is a member of the family Aceraceae, along with the Box Elder and a number of other maples, both native and introduced. Characteristics it shares with these include opposite, palmately lobed, simple leaves (only the Box Elder among our maples has compound leaves) and its distinctive paired samaras, the diagnostic fruits of maples. The Sycamore Maple can be distinguished from other members of the genus Acer by having bright green winter buds. Its leaves are 4-7" across, 5-lobed, and bluntly toothed (Fig. 1). The samara wings are 1.5-2" long, diverging at right angles or less. Acer pseudo-platanus is a native of Eurasia. It is infrequently planted across much of eastern North America, usually in botanical gardens and arboreta and on college and university campuses. It is rarely used as a street tree. Location of Michigan's Big Tree: The tree is located on the grounds of the Lake Bluff Audubon Center near Manistee, Michigan. To reach the tree, take U.S. Route 31 north from Manistee. Where MI Route 110 turns to the left and U.S. Route 31 continues to the northeast, turn left onto MI Route 110. The Lake Bluff Audubon Center is on MI Route 110, 1.8 miles from its junction with U.S. Route 31. The tree is immediately behind the headquarters building of the Lake Bluff Audubon Center. Description of Michigan's Big Tree: The tree is healthy, with a solid, sound trunk. It was measured on 26 July 1995 by the authors. The girth at 4.5' above the ground is 111" (2.8 m). The tree is 53' high (16.3 m), and has an average crown spread of 54' (16.6 m). INVITATION TO PARTICIPATE If you would like to join us in extending this series of articles by visiting and describing one or more of Michigan's Big Trees, please contact Elwood B. Ehrle for help with locations, specifications for taking measurements, and assistance with the manuscript. The Michigan Botanical Club encourages your involvement in this activity. Please remember to ask permission before entering private property.

Page  52 ï~~52 THE MICHIGAN BOTANIST Vol. 39 I. Winter twig, x I. 2. Leaf, x 2. 3. Flowering branchlet, x 2. 4. Staminate flower, enlarged. 5. Perfect flower, enlarged. 6. Fruit, x 2. FIGURE 1. Chacteristics of the Sycamore Maple. The illustration is from Otis, 1931, p. 222, and is used with permission. DEDICATION This series of articles is dedicated to the memory of Paul Thompson, Michigan's Big Tree Coordinator for over 40 years, who died in 1994. LITERATURE CITED Otis, C. H. 1931. Michigan Trees. University of Michigan Press, Ann Arbor. 362 pp.