This note came recently from my friend Sharon Thomason in Dahlonega: “I have fallen in love with the word marcescence. First time I heard it was a few months ago when I heard this young poet David King speak. I was totally captivated by the word — the sound of it and its meaning.”
Actually, marcescence is a botanical term, though poets apparently make use of it, too. It refers to a class of deciduous hardwood trees that retain their dead leaves through winter. Most other deciduous hardwoods drop their leaves by late fall and stand bare until spring.
Marcescence came up a few times last weekend during a late morning stroll in the Big Trees Forest Preserve in Sandy Springs. The occasion was a Georgia Botanical Society “winter tree walk” to help us hone our skills in identifying woody plants by scrutinizing characteristics such as bark, buds, twigs and old leaves.
At the start of our walk, leader Ellen Honeycutt pointed out some marcescent trees at the edge of the parking lot — pin oaks, whose thick canopy of dark brown dead leaves stood out amid the surrounding leafless vegetation.
As she noted, a tree that retains its dead leaves during winter is easier to identify since only a few forest species are marcescent; it narrows down the possibility of what species the tree might be.
Along the trail in the 30-acre preserve, we found other marcescent species, including chalk maple and American hornbeam (or ironwood).
The most noticeable marcescent species, however, was the American beech. Young beeches were starkly visible in the winter woods because of their canopies of light brown withered leaves.
Scientists say an advantage of marcescence is that the unpalatable dried leaves deter browsing by deer in winter. This protects a tree’s delicate twigs and buds, which are essential for the tree to sprout new growth in spring. The retained dead leaves also may help in providing nutrients to a tree in spring.
At any rate, come spring, a marcescent tree’s expanding buds will push off the dead leaves and clothe its branches with new greenery.
In the sky: The moon will be first-quarter Monday, rising around lunchtime and setting around midnight, said David Dundee, Tellus Science Museum astronomer. Mercury and Venus are very low in the west at dusk. Mars sets in the west a few hours after sunset. Jupiter rises out of the east around 8 p.m. Saturn rises out of the east around 3 a.m.
