The Original Mystery Plant
Photo by John Nelson

In a couple of weeks I'll take my botany class on its first field trip of the season. I've got the schedule mapped out, and our first visit will be to a site in the sandhills of central South Carolina. This time of year, of course, nearly all of the leaves of deciduous trees are on the ground. This is an oak we will surely come across.

This oak is most often a small tree, usually not getting any taller than about 40' high. It occurs in a broad area, from New Jersey well into the Midwest, south to lower Texas and the Florida panhandle. It is one of the "red" oaks, and features tiny bristles on the tips of young leaves. It also has acorns that remain on the tree for two seasons before falling. (Species in the "white" oak group lack leaf bristles, and their acorns mature in one season.)

Mature trees commonly have an irregularly- shaped crown. I've often noticed the crowns have a lot of dead, persisting branches hanging on. In very "poor" sites, it may be a somewhat scrubby species, scarcely a tree. The bark is roughly fissured and very dark (almost black), and its wood is quite hard, tough, and durable. Because of the irregular crown and its slow growth, this oak is not as important as a timber species.

Its wood has been used rather unglamorously for fence posts and railroad ties in the olden days and as a source of charcoal. Unfortunately, this species isn't going to win many beauty contests nor has it become popular for landscaping. It's one of a series of species that most people refer to as "scrub" oaks, growing in poor upland soils, in what most would think are desperate habitats.

On the other hand, these trees have plenty of charm. There are several in yards around my neighborhood, which is indeed an urbanized sandhill ecosystem. The trees look quite a bit different from their relatives, and given enough time, can exhibit a sort of bold, craggy look. The leaves are especially handsome and somewhat unusual for oaks. The leaf blades are prominently widened toward the tip, usually exhibiting three sometimes five broadly rounded humps or "shoulders." The leaves are relatively thick and sturdy. They tend to remain on the ground intact rather than crumbling like other oaks' dried leaves during winter. The lower surface of the leaf blade is somewhat dull, soft and felty, but the upper surface of the living leaves, fully expanded, is a bright, lustrous green.

My students will have to wait until well into the semester to see the new leaves, which start unfolding around the beginning of April in our area.

Editor's note: Beginning with this week's issue, we will give the answer to the mystery plant the same week it is published.

Answer to this week's mystery plant

Blackjack oak Quercus marilandica]

Dr. John Nelson is the curator of the USC Herbarium.

To learn more about the Herbarium, call 777-8196. The

department also offers free plant identification.

www.herbarium.org