Chapman's Rhododendron

Rhododendron chapmanii

Description

Chapman's rhododendron, Rhododendron chapmanii, is an evergreen shrub with stiffly ascending branches, ranging from 1.6-6.6 ft (0.5-2.0 m) in height. Somewhat wrinkled, ovate leaves with entire margins are from 1.2-2.4 in (3-6 cm) long. New stems and the underside of leaves usually are covered with reddish-brown dots. Abundant light pink flowers, with funnel-shaped corollas, appear in terminal racemes in early spring.

Individual plants are relatively long-lived. Dry seed capsules cling to the shrub for several years and are found in clusters on almost all plants. Despite the fact that seeds germinate readily in cultivation, little reproduction is occurring in the wild.

Habitat

Chapman's rhododendron requires light shade to full sun, good drainage, sandy soil with abundant organic matter, and a stable, slightly acidic water table near the surface. This type of habitat usually supports a dense stand of broadleaf trees or large shrubs that shade out the rhododendron. Therefore, suitable habitat is found only in transitional zones between longleaf pine forests and titi (Cliftonia) bogs in areas of nutrient-poor and porous soil. Because the layer of well-aerated soil in these areas is thin, much of the associated vegetation is dwarfed.

The rhododendron's habitat has been variously described as sandy pine barrens, low pinelands, pine flatwoods, and borders of titi swamps. Despite the variety of names, the preferred habitat itself is very constant. The plant always occurs adjacent to a titi bog and always occupies a transitional habitat, or ecotone, that is intermediate between pine flatwoods and sand pine scrub. This plant community is adapted to and maintained by periodic fires.

Distribution

Chapman's rhododendron once had a more widespread range. It was found in transitional habitat throughout a band that stretched across the Florida panhandle almost to the Atlantic coast. Today, it is now a rare Florida native, occurring in three widely separated populations—near Port St. Joe in Gulf County; near Hosford in Liberty and Gadsden Counties; and at Camp Blanding in Clay County. The total population was estimated at about 3,000 plants in 1985.

The largest, healthiest, least threatened, and possibly the oldest population is near Hosford, where at least 2,300 plants occur in several widely spaced groupings. The Gulf County population is more widely dispersed, occurring along a line paralleling the coast, five miles on either side of Port St. Joe. The total number of plants was about 600 in 1985, down from about 1,200 plants one year earlier. The decline was caused by logging. The population at Camp Blanding in Clay County numbered about 30 plants in 1985.

Threats

Because Chapman's rhododendron blooms prolifically in early spring, it is considered a valuable ornamental. It has been widely collected for commercial sale and as breeding stock to develop heat-resistant varieties of ornamental rhododendrons. Continued collection threatens the plant's survival in the wild.

The ecotone required by the species disappears after a few decades if fire is suppressed, but it can be maintained artificially by controlled burning, by cutting undergrowth, or by harvesting trees in a particular sequence. Clearing pinelands for commercial slash pine plantations has, in the past, destroyed much of the plant's habitat. Properly managed, silvicultural activities could actually benefit Chapman's rhododendron.

Conservation and Recovery

Management of the rhododendron's habitat should include prescribed burning and removal of excessive oak sprouts. The St. Joe Paper Company, a large landowner in the Florida panhandle, has set aside a preserve for one particularly robust population and has begun habitat management for the rhododendron at other sites. It is hoped that close cooperation between the U. S. Fish and Wildlife Service and private landowners, such as the St. Joe Paper Company, will reap two benefits in the coming years: the conservation and ultimate recovery of Chapman's rhododendron.

Contact

Regional Office of Endangered Species
U.S. Fish and Wildlife Service
1875 Century Blvd., Suite 300
Atlanta, Georgia 30345
http://southeast.fws.gov/

References

Chapman, A. W. 1860. Flora of the Southern United States. Ivison, Phinney, New York.

Godfrey, R. K. 1979. "Chapman's Rhododendron." In D. B. Ward, ed. Rare and Endangered Biota of Florida. Vol. 5, Plants. University Presses of Florida, Gainesville.

U.S. Fish and Wildlife Service. 1983. "Chapman's Rhododendron Recovery Plan." U.S. Fish and Wildlife Service, Atlanta.

U.S. Fish and Wildlife Service. 1979. "Determination of Chapman's Rhododendron, Rhododendron chapmanii, as an Endangered Species." Federal Register 44: 24250.