Bigleaf Maple (Acer macrophyllum Pursh), sometimes known as broadleaf maple or Oregon maple, is a native hardwood tree species that occurs in a narrow band along the Pacific Coast, mainly from Sullivan Bay, BC, south to San Francisco Bay CA. It does occur south of San Francisco all the way to San Diego, but only in isolated pockets. This species always occurs within 185 miles of the coastline.
This tree, being one of the few commercial hardwood tree species in the region, bears unusually large leaves up to 12 inches across (exceptional ones up to 24 inches in width have been documented). In the inland portion of Mendocino County this tree can grow on hot, dry sites, but is usually in association with a moist riparian stream bottom or ravine.
I can think of only four (4) individual Bigleaf Maple trees located on the UC Hopland Research & Extension Center's 5358 acres, so the species can be considered to be rare on the property. The current national champion Bigleaf Maple is near Marion OR and has a DBH (diameter at breast height) of 8 feet 1 inch, is 88 feet tall, and has a crown spread of 104 feet.
