It is then filtered through stacks of sugar maple charcoal. The present name comes from a nearby grove of sugar maple trees. There are a few exceptions such as sugar maple. Rock or Sugar Maple bats are preferred. This is a primary fungus utilized in the spalting of sugar maple and other hardwoods. Maple syrup is made from reduced sugar maple xylem sap. Norway maple seeds are flattened, while those of sugar maple are globose. Germination of sugar maple seed in temperatures above is rare to nonexistent. It takes about of sugar maple sap to make of syrup. There were probably also oak forests that contained no sugar maple. Human influences have contributed to the decline of the sugar maple in many regions. This is because sugar maple has a higher sugar content. The minimum seed-bearing age of sugar maple is about 200 years. They cultivated wild rice ("Zizania" spp.), gathered sugar from sugar maple trees. Cherry, red maple, black birch, and sugar maple became common species in the understory.