SCRUB PLUM geniculata

Photo of Scrub plum foliage and fruit. Photo of scrub plum flower. Photo courtesy of Betty Wargo. Photo courtesy of Shirley Denton.

FAMILY: Rosacea (Rose family)

STATUS: Endangered (Federal Register, January 21, 1987)

DESCRIPTION AND REPRODUCTION: The scrub plum is a scraggly, heavily branched up to 2 meters (6 feet) tall, although 0.5 m (1.5 feet) is more typical at sites with frequent fires. Its twigs are strongly zigzag, with spiny lateral branches. The deciduous leaves have stipules and fine teeth. The white flowers are five-petalled, about 1 to 1.3 centimeters (0.4 to 0.6 of an inch) in diameter. The fruit is a bitter, dull reddish plum, 1.2 to 2.5 centimeters (0.4- to 1-inch) long (Kral 1983). Flowering is in winter (Wunderlin 1982).

RANGE AND POPULATION LEVEL: Scrub plum is native to central Florida: (1) Lake County between Lake Apopka and Clermont; (2) the southwest and northwest corners of Orange and Osceola Counties, respectively; and (3) Polk and Highlands Counties from Lake Wales south to highway 27 near Venus, where the occurs in scrub on the Lake Wales Ridge (Johnson 1981; Stout 1982). It is absent from the Bombing Range Ridge of Avon Park Air Force Range. It is known from 114 locations on 21 sites on the Lake Wales Ridge. A total of 35 of these locations are on managed areas under public ownership (Schultz et al. 1999). This species appears to be stable/increasing on the Lake Wales Ridge State Forest (Weekley 1996). No estimate of the total number of is available.

HABITAT: This plant is found in -turkey oak vegetation in Lake County, and in sand pine ( - evergreen oak scrub vegetation -locally referred to as scrub) in Polk and Highlands Counties. The major evergreen scrub oaks are myrtle oak (Quercus myrtifolia); Chapman oak (Quercus chapmanii); and sand live oak (Quercus geminata).

REASONS FOR CURRENT STATUS: Loss of habitat to residential and agricultural development is the primary factor in the decline of this species. Scrub plum is native to two areas in central Florida. One of these areas, in Lake County, has now been converted almost entirely to groves. The other area, in Polk and Highlands Counties, has largely been developed. The scrub plum is also vulnerable to taking because of its potential value as an attractive ornamental plant. A further threat is that restriction to a specialized habitat and small geographic range tends to intensify any adverse effects upon its populations.

MANAGEMENT AND PROTECTION: Scrub plum plants nearly always resprout after fire (Menges and Kohfeldt 1995; Menges et al. 2005; Weekley and Menges 2001, 2003a, 2003b). Three years after a fire, more than 98 percent of burned plants had survived, though they had lesser height and crown diameter than unburned control plants (Menges et al. 2005). The plant is protected at 12 sites on the Lake Wales Ridge (Schultz et al. 1999). Long-term survival of the species will be contingent upon finding ways to protect a sufficient number of populations, either existing populations or new ones established within the historic range for recovery purposes. Management needs are not known with certainty, but the plum is often found on roadcuts and fire lanes, which indicates that it benefits from moderate disturbance which removes other . Genetic studies in the field would help define the range of germplasm that is currently being protected and help to target genetically important populations that are not on conservation lands (T. Race, Bok Tower Garden, pers. comm. 2000).

REFERENCES:

Johnson, A.F. 1981. Scrub Endemics of the Central Ridge, Florida. Unpublished Report Prepared for U.S. Fish and Wildlife Service.

Menges, E.S. and N. Kohfeldt. 1995. Life history strategies of plants in relation to fire. Bulletin of the Torrey Botanical Club 122(4):282-297.

Menges, E.S., C.W. Weekley, and M.A. Rickey. 2005. Sandhill restoration studies and experimental introduction of Ziziphus celata at Lake Wales Ridge National Wildlife Refuge (Carter Creek). Annual report No. 1 (January), project NG02-002, contract 03148.

Kral, R. 1983. A Report on Some Rare, Threatened, or Endangered Forest-related Vascular Plants of the South. USDA Forest Service, Technical Publication R8-TP2, x + 1305 pages.

Schultz, G.E., L.G. Chafin, and S.T. Krupenvitch. 1999. Rare Plant Species and High Quality Natural Communities of Twenty-Six CARL Sites in the Lake Wales Ridge Ecosystem. Final Report of Florida Natural Areas Inventory for U.S. Fish and Wildlife Service. 202 pages.

Stout, I.J. 1982. Descriptions of 894 Strands of Florida Sand Pine Scrub Vegetation. Unpublished Data Prepared for U.S. Fish and Wildlife Service.

U.S. Fish and Wildlife Service. 1987. Endangered and Threatened Wildlife and Plants: Determination of Endangered or Threatened Status for Seven Florida Scrub Plants. Federal Register 52(13):2227-2234.

Weekley, C. 1996. Progress Report: Lake Wales Ridge Scrub Plant Monitoring and Management Project. Florida Plant Conservation Program/Florida Division of Forestry, Lake Wales Ridge State Forest. 10 pages.

Weekley, C.W. and E.S. Menges. 2001. Demography, floral biology, and breeding system of scrub plum (Prunus geniculata), a federally listed endangered plant. Report to U.S. Fish and Wildlife Service; Jacksonville, Florida. 14 pages.

Weekley, C.S. and E.S. Menges. 2003a. Species and vegetation responses to prescribed fire in a long- unburned, endemic-rich Lake Wales Ridge scrub. Journal of the Torrey Botanical Society 130(4):265-282.

Weekley, C.W. and E.S. Menges. 2003b. Demography, floral biology, and breeding system of scrub plum (Prunus geniculata), a federally listed endangered plant. Report to U.S. Fish and Wildlife Service; Jacksonville, Florida. 9 pages.

Wunderlin, R.P. 1982. Guide to the Vascular Flora of Central Florida. University Press of Florida, Gainesville. 472 pages.

For more information please contact:

Dawn Zattau U.S. Fish and Wildlife Service 6620 Southpoint Drive South, Suite 310 Jacksonville, Florida 32216 904/232/2580 [email protected]

Last Updated: 08/2005 Last Reviewed: 08/2005