Each season has characteristic features that signal its arrival. Winter is no exception. Two of my winter favorites: mistletoe and sycamore.
Coon Cove — the name assigned to our valley on a late 19th century deed — is surrounded on three sides by steep ridges, the crests of which mark the boundary with the Great Smoky Mountains National Park. By the time my wife and I get home during the winter months, the evening sun is setting behind the southwestern rim of the cove. This illuminates a stand of white oaks situated along the highest ridge. Globular clusters of mistletoe decorate the bare branches, glowing with pristine intensity. It’s not difficult at that moment to comprehend why mistletoe has for so long been a green emblem of renewal.
Numerous bird species — notably cedar waxwings and bluebirds — are inordinately fond of the translucent white mistletoe berries that mature in November and December. Mistletoe seeds are coated with a sticky substance (viscin) that cause them to stick to the beaks and claws of foraging birds. Birds are tidy critters. When they pause to clean themselves on tree limbs, they unwittingly distribute mistletoe seeds from treetop to treetop throughout the woodlands. These germinate and penetrate their hosts via short root-like structures (haustorium).
Late nineteenth century anthropologist James Mooney recorded that the Cherokees noted that mistletoe “never grows alone but is found always with its roots fixed in the bark of some supporting tree or shrub from which it draws its sustenance.” And so they “called it by the name ‘uda’li,’ which signifies ‘it is married.’”
When the last leaves drop from the trees, it’s past time to get serious about winter and hope you’ve got enough firewood in place. One type of wood, however, that won’t do much in the way of providing heat is sycamore. The stuff is just about impossible to split. Axes bounce off. That’s because the grain of sycamore wood is peculiar. Indeed, everything about the woody structure of the tree is peculiar.
Wood grain is determined by the alignment of the xylem cells within a given tree species. These cells form the woody tissue that conduct water and nutrients and help support the tree. In woods that split easily, the xylem cells lie in a parallel plane. That’s why it’s such a pleasure to pile up kindling from, say, tulip poplar.
Some trees are difficult to split because their cell structures are slightly irregular or even spiraled. But sycamore takes the cake — its cells alternately spiral right-handed and then left-handed in successive years, resulting in an interlocked arrangement that has been accurately described as “an ax-wielder’s nightmare.”
The outer covering of the tree is as peculiar as its inner grain. Go to the base of most any large sycamore specimen and you’ll find bark plates that have scaled off the upper trunk and limbs. The technical term for this is “exfoliation.” Apparently the outer bark isn’t able to stretch as the tree grows and is cast off. It has been theorized, but not proven, that sycamore can gather additional light-giving energy by doing so. At any rate, serpent-like, the species sheds its “skin,” exposing whitish inner bark that catches the slanting evening light and gleams like a beacon, signaling winter.