A single genus, acer, includes from sixty to seventy species, widely distributed over the Northern Hemisphere. A single species goes south of the equator, to the mountains of Java. All produce pale close-grained, fairly hard wood, valued in turnery and for the interior finish of houses. The clear sap of some American species is made into maple sugar.
The signs by which we may know a member of the maple family are two: opposite, simple leaves, palmately veined and lobed; and fruits in the form of paired samaras, compressed and drawn out into large thin wings. No amount of improvement changes these family traits. No other tree has both leaves and fruits like a maple's.
The distribution of genus acer is interesting. The original home of the family is in the Far East. In China and Japan we may reckon up about thirty indigo maples, while only nine are native to North America. Of these, five are in the eastern half of the continent, three in the West, and one grows indifferently on both sides of the Great Divide.
The Sugar Maple
Acer saccharum, Marsh.
The sugar maple (see illustration, [page 198-199]) is economically the most important member of its family in this country. As an avenue and shade tree it is unsurpassed. It is the great timber maple, whose curly and bird's-eye wood is loved by the cabinet-maker; and whose sap boiled down, yields maple sugar—a delicious sweet, with the distinctive flavor beloved by all good Americans. In October the sugar maple paints the landscape with yellow and orange and red. Its firm broad leaves, shallowly cleft into five lobes, are variously toothed besides. The flowers open late, hanging on the season's shoots in hairy yellow clusters. The key fruits are smooth and plump, with wings only slightly diverging. They are shed in midsummer.
Hard maple wood outranks all other maple lumber, though the curly grain and the bird's-eye are accidental forms rarely found. Flooring makes special demands upon this wood. Much is used in furniture factories; and small wares—shoe lasts, shoe pegs and the like—consume a great deal. As fuel, hard maple is outranked only by hickory. Its ashes are rich in potash and are in great demand as fertilizer in orchards and gardens.
The living tree, in the park, on the street, casting its shade about the home, or glowing red among the trees of the woods, is more valuable than its lumber. Slow-growing, strong to resist damage by storm, clean in habit and beautiful the year round—this is our splendid rock maple. Rich, indeed, is the city whose early inhabitants chose it as the permanent street tree.