Florida Bonamia

Bonamia grandiflora

Description

Florida bonamia, Bonamia grandiflora, is a perennial vine with sturdy, prostrate stems growing about 3 ft (1 m) long. Stems bear leathery, oval leaves up to 1.6 in (4 cm) long. The only morning glory vine of the scrub with large blue flowers, its blooms a funnel-shaped corolla and a pale center, similar to the cultivated variety of morning glory, Heavenly Blue. Flowers are solitary in the leaf axils. The fruit is a capsule.

Habitat

Florida bonamia is restricted to sand pine scrub vegetation, typically consisting of scrub oaks, sand pines, and associated plants. Sandy clearings between the trees are scattered with lichens and herbs. Natural fires are infrequent but very intense and maintain a patchwork of clearings within the scrub. When fire is suppressed, the clearings are taken over by woody growth and maturing vegetation.

In Highlands and Polk counties, the plant is associated with other scrub plants, several of which are federally listed: the Highlands scrub hypericum (Hypericum cumulicola ), papery whitlow-wort (Paronychia chartacea ), and scrub plum (Prunus geniculata ). In Orange County, bonamia occurs with the Endangered scrub lupine (Lupinus aridorum ).

Distribution

This plant is endemic to sand pine scrub habitat in peninsular Florida. It was formerly distributed from Volusia and Marion counties south to Sarasota and Highlands counties.

Populations are known from a number of sites in the Ocala National Forest in Marion County. There, plants are typically limited to marginal, sandy strips of land along forest edges and to burned-over lands, where there is full sun.

South of the forest, the plant occurs at sites in Hardee, Highlands, Polk, and Orange counties. Protected populations are considered somewhat stable, although the five known sites for the plant in Orange County are all on small remnants of scrub vegetation or vacant lots surrounded by houses or orange groves west and southwest of Orlando, one of the fastest growing urban areas in the United States.

Threats

Florida bonamia is threatened by continuing loss of habitat. By 1981, nearly 65% of the native scrub vegetation in Highlands County had been displaced, primarily by construction of roads and housing subdivisions. An additional 10% of the scrub was considered "seriously disturbed." Remaining tracts of scrub in the county are rapidly being developed as housing or citrus groves. Polk County has experienced similar habitat loss, mostly due to conversion of land to citrus groves. Remaining sites in Orange County are in remnant patches of habitat, such as vacant lots.

Conservation and Recovery

The Nature Conservancy protects a population at the Tiger Creek Preserve in Polk County, and land acquisition related to the preserve continues. Further expansion of the state of Florida's Saddle Blanket Lakes Preserve would also protect suitable habitat for the species. The management plan of the Ocala National Forest already limits access to off-road vehicles and prescribes measures to maintain a range of successional stages in the habitat.

The state of Florida is expanding its land holdings in the central portion of the state to provide refuge for the many rare and endangered scrub plants. In the late 1980s, the pace of state land acquisition was stepped up in response to the increased rate of residential development.

Designation of Critical Habitat for the Florida bonamia was deemed imprudent by the U. S. Fish and Wildlife Service (FWS) and Forest Service personnel. They believed that publishing the required maps and detailed descriptions of sites might attract collectors to this plant because of its showy flowers and potential for horticultural use.

However, the FWS did include the species in its draft of the Recovery Plan for Nineteen Florida Scrub and High Pineland Plants, first announced 1995. The plan, a revision and expansion of a 1990 recovery plan covering 11 plant species, outlines actions deemed necessary to restore the scrub plum and other endangered plants, including habitat protection through land purchase and other means (including the Habitat Conservation Plan process for threatened animals in the Florida scrub habitat); the management of protected habitats; and the assessment of progress and plan post-recovery monitoring.

The 1990 recovery plan emphasized the need for land acquisition to protect these plants. At the time, the state and private organizations had already made significant acquisitions, and more have been accomplished since then (including initial land purchase for the Lake Wales Ridge National Wildlife Refuge). These land purchases, accompanied by the other elements of the recovery plan, are likely to assure the full recovery or at least the downlisting of the large majority of the 19 plants, including the Florida bonamia.

Contact

Regional Office of Endangered Species
U.S. Fish and Wildlife Service
1875 Century Blvd., Suite 200
Atlanta, Georgia 30345
http://southeast.fws.gov/

References

Austin, D. F. 1979. "Florida bonamia." In D. B. Ward, ed., Rare and Endangered Biota of Florida ; Vol.5, Plants. University Presses of Florida, Gainesville.

Johnson, A. F. 1981. "Scrub Endemics of the Central Ridge, Florida." Report to the U.S. Fish and Wildlife Service, Atlanta.

Wunderlin, R., D. Richardson, and B. Hansen. 1980."Status Report on Bonamia grandiflora." Report to the U. S. Fish and Wildlife Service, Atlanta.