Pygmy Fringe-tree

Chionanthus pygmaeus

Description

The pygmy fringe-tree, Chionanthus pygmaeus, is a long-lived woody bushy shrub of the olive family, usually less than 3 ft (1 m) tall. A few individuals may grow significantly larger under ideal conditions. New stems sprout from older branches that are buried by blowing sand. Deciduous leaves with entire margins are arranged alternately along the stems. The leathery blades are elliptical with rounded ends; the upper surface is a dark yellow-green and the underside is paler. Flowers bloom in showy clusters (panicles) in late March. Fused petals are linear and white.

Leafing and budding occur in mid-March, an-thesis in late March to early April, fruiting around June, and seed dispersal in September. Pollen is disseminated by insects, mainly honey bees. The fleshy part of the fruit is astringent and probably not attractive to birds. However, the seed is eaten by many animals, including deer, turkeys, and quail.

Pygmy fringe-tree is closely related to the common fringe tree (C. virginicus ), which is cultivated as an ornamental.

Habitat

The pygmy fringe-tree occurs within sand pine scrub but is most abundant in open, sandy areas where sand pines are relatively scarce. These open areas are maintained by brush fires that occur about every 30 years. Although relatively infrequent, these fires are very intense and open up large unshaded clearings. After a fire, the pygmy fringe-tree renews itself from buried branches or from seed and grows without competition from other plants. It is often found in association with the scrub plum (Prunus geniculata ), another federally endangered species.

Distribution

Pygmy fringe-tree once grew throughout the sand pine scrub region of central Florida. It was first collected in 1894 near Eustis and later from sand dunes between Avon Park and Sebring. When listed in 1987, this species was known from over 20 sites in Polk, Highlands, Lake, and Osceola counties. Since its listing, nearly 50 populations have been identified, most consisting of only a few plants. Because multiple above-ground shoots grow from buried stems, the number of genetically distinct plants is hard to estimate.

The pygmy fringe-tree is found from west of Lake Apopka in Lake County to northwestern Osceola County, and along the Lake Wales Ridge in Polk and Highlands counties, an area that includes the Saddle Blanket Lakes and Highlands Hammock State Park. Only plants inside Highlands Hammock State Park and The Nature Conservancy's Saddle Blanket Lake tract are currently protected. The pygmy fringe-tree may also occur at Fort Cooper State Park south of Inverness (Citrus County).

Threats

Much of the former habitat of the pygmy fringe-tree has been converted for citrus groves or for residential subdivisions. Remaining tracts of scrub have been degraded by suppression of fire, which allows plants of a later successional stage to dominate. The pygmy fringe-tree does not tolerate shade or extensive competition from other plants.

Conservation and Recovery

The pygmy fringe-tree is cultivated and sold by at least two nurseries, but preserving the tree in the wild will depend on acquisition of remaining tracts of sand pine scrub. The Florida Natural Inventory has proposed state acquisition of several parcels of scrub land—the largest comprising more than 1,000 acres (405 hectares). The Nature Conservancy purchased land containing pygmy fringe-tree habitat at Tiger Creek and Saddle Blanket Lakes in Polk County. These nature preserves are protected from off-road vehicles. Controlled burning at protected sites will be needed to maintain the open sandy areas that are preferred by this species.

Contact

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

References

Abrahamson, W. G. 1984. "Post-Fire Recovery of the Florida Lake Wales Ridge Vegetation." American Journal of Botany 71: 9-21.

Abrahamson, W. G., et al. 1984. "Vegetation of the Archbold Biological Station, Florida." Florida Scientist 47: 209-250.

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

U. S. Fish and Wildlife Service. 1987. "Endangered Status for Seven Florida Scrub Plants." Federal Register 58: 2234