Sometime in mid-March, after the eastern phoebes have returned, our red maple tree buds turn a deeper scarlet, adding welcome color to our forest. Shortly thereafter I catch the faint scent of their opening red and orange flowers.
The clusters of dangling, bell-shaped red flowers with red forked tongues (stigmas) are female while the orange blossoms fringed with long yellow stamens that resemble old-fashioned shaving brushes, are male. Seen through a hand lens, the blossoms are lovely. At a distance their orange, red, and yellow combination is a pale reflection of autumnal color. Whole hillsides, especially in northern Pennsylvania, glow with their spring tints and signal that once again spring has truly arrived, even though they blossom when night temperatures are still below freezing.
Some trees are male, some are female, and some are both male and female, although in the latter case the male and female flowers are on separate side branches. For the most part, red maples are wind-pollinated, but that faint odor I detect also attracts early pollinating insects.
Red maples, seemingly in a hurry to bloom ahead of other tree species, also flower before they leaf out so that the leaves won’t block the movement of pollen from male to female flowers. A month after pollination, the female flowers have matured into dark red, double samaras or winged fruits more popularly known as “keys,” “helicopters,” or “whirligigs.” Each wing contains a seed that our chipmunks, gray and fox squirrels seem eager to consume after a long, hard winter, especially if the previous fall’s acorn crop has been sparse.
The red maple Acer rubrum, which means “red maple,” was named by the Swedish taxonomist, Carl Linnaeus, back in the eighteenth century. His student, Peter Kalm, traveled to North America in 1748 and stayed until 1751, living mostly in southern New Jersey’s Swedish colony or in eastern Pennsylvania. During a visit to Chester, Pennsylvania and its environs in 1748, Kalm wrote about red maples. They were plentiful trees that grew mostly in swampy, wet places. From their wood the colonists made plates, spinning wheels, spools, and feet for chairs and beds. They used the bark to concoct a blue dye and a “good, black ink.”
Today, red maples grow from sea level to 3000 feet and from swamps and bogs to dry mountaintops. They average 50 feet in height but can reach 60 to 90 feet under good conditions with a trunk diameter of between 18 and 30 inches. They are found from Manitoba to southern Newfoundland in Canada, south to central Florida and west to east Texas—the widest ranging tree species in North America.
Their leaves, like all maples, grow opposite one another on their branches. They have three to five lobes and are coarsely toothed along their edges. Dark green and shiny above, “its leaves are white or silvery on the under sides, and, when agitated by the wind, they make the tree appear as if it were full of flowers,” Kalm wrote. That has led to two of their alternate names– “silver maple” and “white maple.” Their leaf stems are usually red and their branchlets green at first, but then they become smooth and red. They have V-shaped leaf scars (where last year’s previous leaves have fallen off) that do not encircle their stems, and each scar contains three bundle scars (tiny, raised spots inside a leaf scar where the leaf has broken off). Their pith, which occupies the central portion of their twigs, branchlets, and roots, is pinkish and rarely increases in size after a tree’s first year.
We have four good-sized red maples growing along our driveway. On the streamside below our house, one red maple is 19 inches diameter at breast height (dbh) and the other is 20 dbh. Both are hoary with whitish crustose lichens and patches of green moss. The 19-inch tree was the favorite climbing tree of our three sons because it has a short trunk and wide limbs within easy reach of the ground. Both trees have shed branches and woodpecker holes.
The third tree, outside the guesthouse, is 18 inches dbh and is almost dead. Branches and long pieces of bark lie on the ground, and it is riddled with woodpecker holes including a large, vertical, pileated woodpecker food excavation hole. Still, one large branch bears the buds for next season’s flowers and leaves.
The largest and healthiest yard red maple grows down next to an old corral area below the guesthouse. It is 23 inches dbh, and our son Dave claims it may be the largest red maple on our 648 acres.
Red maples are relatively short-lived, reaching maturity at 70 to 80 years. Their branches are easily injured by wind storms, ice storms, and heavy snows, and their thin bark doesn’t heal quickly when it is drilled by woodpeckers in search of insects or by yellow-bellied sapsuckers and squirrels after the sweet sap of red maple trees. These wounds allow fungi to invade, most notably Inonotus glomeratus, which infects branch stubs and stem wounds, Oxyporus populinus, which forms small, white fruit bodies often beneath patches of moss, and Phellinus igniaris, which causes heart rot that, in turn, leads to a wind-snapped tree trunk or whole tree. No doubt that is what has invaded our guesthouse tree.
In addition, the gallmaking maple borer, maple callus borer, and scale insects can damage red maples and the elm spanworm can defoliate it.
Still, red maples are incredibly successful trees. They are prolific and early seed producers. Trees as young as four years bear samaras, and a tree one foot in diameter has as many as one million seeds. Almost every year they produce seeds, and every two years they have a bumper crop.
Before Europeans arrived in eastern North America, red maples represented less than five percent of the forest. Today many forests consist of 30 to 40 percent red maples, and they are the most abundant forest trees in Pennsylvania. Two of their alternate names are “swamp maple” and “water maple” because they used to grow only in wetland conditions — swamps, bogs, and wet forests as Kalm reported. But when their competitors on higher, drier ground died of disease, namely the American chestnut and American elm, and loggers selectively removed yellow birch, sugar maple, and oaks, shade tolerant red maples moved right in.
Then too deer numbers increased, and although they do browse on red maple seedlings, they prefer oaks and other hardwoods. Besides, red maples are prolific sprouters and spring up faster than oaks so they quickly grow beyond deer range.
Fire suppression has also favored red maples because their thin bark is easily damaged by fire whereas oaks, with their thick bark, deep roots, and dormant buds near or below the soil line that quickly germinate, can survive and even thrive under low level fires.
Acid rain has altered our forest soils, which is still another reason for the proliferation of red maples. They like acidic soil and oaks do not.
Red maples can withstand floods as long as 60 days because of their 80 feet of long woody roots that anchors them firmly to a sodden earth.
Drought doesn’t bother them much either. They merely stop growing until conditions improve and then produce a second growth flush.
Killing red maples isn’t easy as foresters and landowners have discovered because red maples are resistant to herbicides and girdling.
In our hundred-year-old forest, we have far more oaks than red maples, and in our three-acre deer exclosure, with its two-hundred-year-old trees, we have many more oak seedlings than red maple seedlings. But on our former neighbor’s 125-acre property that was logged before we bought it, they left some white, black and red oak seed trees, as well as a few tulip poplars and bitternut hickories. However, due to deer, there are few if any oak seedlings after 20 years, so in early spring I visit that portion of our land to savor red maple color.
For fall color, I hike over to a neighboring property that was also cut before it was sold more than 40 years ago. It is now a red maple forest that glows with a palette of colors almost as lovely as that of New England’s famed sugar maples.
While red maples may not be as useful to humans as oaks or sugar maples, their sap can be boiled for syrup and their wood used for furniture veneer, gun stocks, tool handles, pallets, plywood, oars, barrels, crates, flooring and railroad ties. But first and foremost, they are valuable ornamental and shade trees, although they are sensitive to ozone injury, which makes them less valuable as city street trees.
Native Americans too found red maples useful, especially infusions of their bark for treating hives, dysentery, women’s problems, and sore eyes. They used red maple wood to make baskets and for carving.
Some wild creatures also appreciate red maples. Porcupines eat their bark and flowers, and songbirds, squirrels, and mice eat their seeds. Along with deer, snowshoe hares also like their sprouts. Eastern screech owls, wood ducks, pileated, downy, and hairy woodpeckers and common flickers nest in their cavities. Prairie warblers like to build their open nests in red maples three to six feet high.
Cattle and horses aren’t so fond of red maples because their leaves, particularly if they are wilted or dead, are toxic to them especially in summer and late fall.
But why are they called “red” maples? Nancy Ross Hugo in her delightful book Seeing Trees: Discover the Extraordinary Secrets of Everyday Trees says that they were probably named for their flowers.
Donald Culross Peattie in A Natural History of Trees of Eastern and Central North America gives a more nuanced and poetic explanation, mentioning their red leaf stems in summer and their color in fall.
“In winter,” he writes, “the buds are red, growing a brilliant scarlet as winter ends, the snow begins to creep away, and the ponds to brim with chill water and trilling frog music… no other tree quite equals them at this season in quality or intensity of color… The flowers too are generally red, sometimes yellow, and, minute though they are, they stand out brilliantly.” Even their early leaves, when still small, are scarlet “as they unfold from their fanwise crumpling in the bud.” So too, are those deep red samaras dangling from the trees in May.
All in all, red maples celebrate the color red throughout the year.
All photos in this column are by Dave Bonta. Click on them to see larger versions on Flickr.