Thursday, January 31, 2013
Here's a cold winter moon, slowly rising and bathing the trees below with its pale gold light. Winter is a good time to remember that in the world around us, natural processes are still very much occurring, although often slowed down a good bit. And it's time to remember that the days are starting to get longer now, and it won't be long before more and more flowers will be popping out.
The flowers of the small tree pictured here are associated with the large, globose "floral" buds at the ends of the twigs. When these buds open, you will see a very familiar sight indeed: four bright white bracts (sometimes pink) surrounding a cluster of tiny yellowish-green flowers. Everybody has seen these opening in March. And most people think that the flower bears four bright, white petals. (Nope.) Trees in full bloom are without doubt one of the showiest and most characteristic displays in the forests of eastern North America, and it is not really a surprise that this species is one of the most popular flowering trees in cultivation, now widely grown around the world. The flowers in each cluster eventually form one-seeded fruits, which as they mature, go from green to shiny, bright red in the fall. These fruits are nutritious and are enormously popular with a great many birds and mammals, and thus the tree is commonly spread by wildlife.
The leaves start to expand after the blooming has begun, and each mature leaf is egg-shaped, bright green, and about four inches long. In the autumn, the leaves turn a sort of red or russet. Once they've fallen, the leaves rapidly decompose, returning their nutrients to the ground more quickly than the leaves of most other trees. The wood is hard and dense, and has been used historically as the building material for shuttles and looms in old-time mills. Its blossoms are the state flower of North Carolina, and it is the state tree of Virginia (their state flower, too). Unfortunately, this species is rather susceptible to various fungal diseases, and there is some threat now to natural and cultivated populations from a disease called "anthracnose."
This plant is a common component of high-ground forests from southern New England through the upper Midwest, and south to eastern Texas and northern Florida. It is what we call an "understory" species, that is, usually not a part of the higher canopy. Because of this, you would think that this species must be able to tolerate considerable shade…which is true. In cultivation, though, it is able to withstand open, sunny sites, as well, but it seems to do the best with at least some shade. Everybody will instantly recognize it when looking at its gorgeous spring flowers and brilliant autumn fruits, but in the winter, the best way to identify it is by its bark…
[Answer: “Dogwood," Cornus florida]
John Nelson is the curator of the A. C. Moore Herbarium at the University of South Carolina, in the Department of Biological Sciences, Columbia SC 29208. As a public service, the Herbarium offers free plant identifications. For more information, visit www.herbarium.org or call 803-777-8196.