* Botany Circular No. 18
RHODODENDRON CHAPMANII, AN ENDANGERED S PCIES .*'" '0D 87
ON BOTH STATE AND FEDERAL LISTS 0 X ForWf
K. R. Langdon
The species of Rhododendron native to Florida are divided into 2 subgenera,
subgenus Rhododendron, commonly called rhododendrons, and subgenus Azalea, commonly
called azaleas. Chapman's rhododendron, Rhododendron chapmanii Gray, (Fig. 1),
endemic to Florida (that is, it grows nowhere else), is our only native rhododendron.
Fig. 1. Chapman's rhododendron, Rhododendron chapmanii
(DPI neg. #702411-5)
Rhododendron chapmanii (sometimes classified as R. minus Michx. var. chapmanii
(Gray) Duncan & Pullen) is an attractive evergreen shrub up to around 2 m tall. It
produces rose-pink flowers 3 cm long in clusters in the early spring. It is rare
and occurs in only 3 areas. In the past Chapman's rhododendron was more widely
distributed, but now, because of land clearing, site preparation for pine planting,
land drainage, collecting, and other disturbances, it has been reduced to a rela-
tively few remaining plants. The largest population of these plants is in an area
near the Gadsden-Liberty County line. A small population remains in Gulf County,
and an even smaller (less than 50 plants known) (5,6) disjunct population in Clay
DESCRIPTION: Evergreen shrub up to 2 m tall, branching relatively open and erect-
ascending. Young twigs, petioles, and lower leaf surfaces copiously lepidote scaly,
scurfy dotted, upper leaf surface less so. Leaves alternate, elliptic or oval,
coriaceous, 1.5-5 cm long, 1-3 cm broad, dark green and sometimes dotted above, brown
Botanist, Office of Systematic Botany, P. 0. Box 1269, Gainesville, FL 32602
scurfy bel6i, margins entire, revolute, apex rounded to rarely acute, petioles 2-6
mm long. Flower clusters appearing usually before leafy shoots of the season.
SPedicels 5-8 mm long; calyx united below, shallowly saucer-shaped, persistent, lobes
j minute, triangular, ciliate; corolla united below, light pink to rose-pink, tube
Sfunnelfa-,l-2 cm long, limb 3-4 cm across, lobes ovate to oblong, rounded; stamens
S10, filgpents glabrouN, 2.5 cm long, longer than style; ovary superior, 5-locular,
8Wiles YIierous in each locule, style slender, curved, stigma capitate. Capsule
about 1 cm long, legitudinally lobed, somewhat urceolate in outline (1,2,3,4).
DISCUSSION: The lorida legislature passed a law repealing and replacing the old
plant protection law, Section 865.06, Florida Statutes. This new law, Section
581.185, Florida Statutes, passed in .1978 and revised in 1980 includes R. chapmanii
as one of the tit'ed endangered plants. This law prohibits collecting, transporting,
or selling the listed endangered plants without a proper permit. The U.S. Department
of the Interior, Fish and Wildlife Service listed R. chapmanii as endangered in 1979
(5,6). This lisping affects only commerce or federal or federally funded projects.
The two listings together will offer some hope of preventing the extinction of this
Chapman's rhododendron is an attractive ornamental shrub for cultivation and is
the only species of subgenus Rhododendron satisfactorily adapted to Florida and
other areas of the Deep South along the Gulf and southern Atlantic coastal plain. A
few nurseries have started propagating it from seed and, although quantities are
very limited, legally grown material is available commercially. In no case should
plants be removed from the wild.
Many excellent rhododendron hybrids and cultivars derived from other species
are available for more northerly areas. Hybridization between Chapman's rhododendron
and some of these choice selections might provide a much wider selection of cultivars
adapted to Florida. Commercial production from seed of pure R. chapmanii or hybrids
of it with other selections should reduce the collecting pressure on these rare,
1. Bowers, C. G. 1936. Rhododendrons and azaleas. MacMillan, New York. 549 pp.
2. Godfrey, R. K., and J. W. Wooton. 1981. Aquatic and wetland plants of the
southeastern United States. Dicotyledons. Univ. of Georgia Press, Athens.
3. Robinson, A. F., Jr., ed. 1980. Endangered and threatened species of the
southeastern United States. USDA Forest Service, Looseleaf, unnumbered
4. Small, J. K. 1933. Manual of the southeastern flora. Univ. North Carolina
Press, Chapel Hill. 1554 pp.
5. U.S. Dept. of the Interior, Fish and Wildlife Service. 1979. Determination
that Rhododendron chapmanii is an endangered species. Federal Register
6. .1979. Chapman rhododen-
dron endangered. Endangered Species Technical Bulletin 4(5):6.
7. Ward, D. B., ed. 1979. Rare and endangered biota of Florida. Vol. 5. Plants.
University Presses of Florida, Gainesville. 175 pp.
Contribution No. 19, Office of Systematic Botany.