Most local trees bloom in the spring or early summer, but sourwood (Oxydendrum arboreum) waits until summer is well underway to grow its graceful clusters of small white flowers. These clusters arch out from the tips of twigs and, although each flower is quite small, the mass of flowers is visible from some distance. Bees love the nectar of this tree and in places where sourwood is plentiful “sourwood honey” is considered a fine complement to a slice of bread (I’m afraid that my bee-keeping knows no such temporal precision — whatever the bees gather over the course of the summer is what I get in the jar).
Sourwood is something of a botanical misfit. It grows as a small tree, yet its closest local relatives in the “Heath” family (Ericaceae) are all shrubs or tiny herbaceous flowers: mountain laurel, blueberry, azalea, wintergreen, and so forth. Like these kin, sourwood grows mostly on poor, acidic soils and relies on symbiotic fungi to help its roots find nutrients in these challenging conditions. Sourwood doesn’t quite fit with the “trees” either. Even when full grown, it is never as large as the oaks and hickories with which it grows; its trunk is seldom straight, usually leaning to one side; and, like its cousins the shrubs, it often sprouts more than one stem from the base.
The kinship to blueberries is evident in the flowers which are shaped like urns or bells. Unlike blueberries, sourwood fruits are, unfortunately, mere dry capsules.