Highlands Scrub Hypericum
Highlands Scrub Hypericum
|Listed||January 21, 1987|
|Family||Hypericaceae (St. Johns-wort)|
|Description||Wiry-stemmed, herbaceous perennial with needlelike leaves and numerous yellow flowers.|
|Habitat||Lake Wales Ridge; sand pine scrub, evergreen oak scrub, and rosemaryscrub vegetation.|
|Threats||Agricultural and residential development; fire suppression.|
Highlands scrub hypericum (Hypericum cumulicola ) is a wiry-stemmed perennial herb that grows up to 2 ft (60 cm) tall. Branched stems bear widely spaced pairs of short needlelike leaves. In June, numerous flowers bloom in the upper forks. Each flower has five bright yellow petals (arranged like the blades of a window fan) and numerous stamens. The fruit, a red to brown capsule, produces a large number of minute seeds in October and November. Mature plants flower and fruit vigorously every year. The flowers open early in the morning and are often wilted by the afternoon.
Highlands scrub hypericum is associated with sand pine scrub, evergreen oak scrub, and rosemary scrub vegetation. It shares patches of sunny, relatively barren sand with Cladonia lichens such as reindeer moss and with other endemic herbs, including the federally endangered snakeroot (Eryngium cuneifolium ). Hypericum is adapted to naturally occurring fires in its environment. Without periodic fire, undergrowth must be thinned mechanically or by controlled burning. Otherwise, woody plants invade, shading and crowding out scrub plants. The habitat area that supports the Highlands scrub hypericum consists of prevalent topographic features (i.e., relic dunes) created during the Pleistocene era. It is restricted to moderately or excessively well-drained sand or fine soils with little clay or silt, rapid permeability, and low available water capacity.
Many species of the genus Hypericum are found along the southeastern coastal plain. Highlands scrub hypericum was first described in 1924 from specimens collected between Avon Park and Sebring, Florida. The species has been found at 36 sites throughout the sand pine scrub region of central Florida. Highlands scrub hypericum is currently found in limited numbers at 11 scattered sites along the southern Lake Wales Ridge. Pockets of remaining habitat occur from Frostproof and Lake Arbuckle south to Venus, in Highlands and Polk counties. The Lake Wales Ridge is the habitat of many federally listed species, including scrub mint (Dicerandra frutescens ), scrub lupine (Lupinus aridorum ), and wireweed (Polygonella basiramia ), as well as many species that are candidates for federal listing.
Highlands County is an important citrus producer, and much of the hypericum's scrub habitat has been converted to citrus groves. By 1981 more than half of the scrub vegetation in the southern ridge sandhills community had been lost. Remaining scrub is rapidly falling to proliferating residential subdivisions.
Conservation and Recovery
Three populations are protected at Archbold Biological Station and on the Nature Conservancy's Lake Arbuckle Preserve. The Florida Natural Areas Inventory has sought state acquisition of scrub habitat in Highlands and Polk counties. In addition, the U. S. Fish and Wildlife Service (FWS) is establishing a national wildlife refuge to unite disparate parcels of scrub into a larger regional park.
Recovery efforts for this species are outlined in the "Recovery Plan for Nineteen Florida Scrub and High Pineland Plants," first announced in draft form by the FWS in 1995. The recovery plan outlines basic elements necessary to restore the hypericum and other endangered plants, including 1) habitat protection through land purchase and other means, 2) the management of protected habitats, and 3) the assessment of progress and post-recovery monitoring. This plan is a revision and expansion of a recovery plan (published in 1990) that covered 11 of these plant species. The 1990 edition 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 in question, including the Highlands scrub hypericum.
U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
1875 Century Blvd., Suite 200
Atlanta, Georgia 30345
Abrahamson, W. G. 1984. "Post-Fire Recovery of the Florida Lake Wales Ridge Vegetation." American Journal of Botany 71: 9-21.
Abrahamson, W. G., A. F. Johnson, J. N. Layne, and P. A. Peroni. 1984. "Vegetation of the Archbold Biological Station, Florida." Florida Scientist 47: 209-250.
U. S. Fish and Wildlife Service. 1995. "Recovery Plan for Nineteen Florida Scrub and High Pineland Plants." Draft. U. S. Fish and Wildlife Service, Atlanta.
Ward, D. B., ed. 1979. Rare and Endangered Biota of Florida. Vol. 5: Plants. University Presses of Florida, Gainesville.
Wunderlin, R. P. 1982. Guide to the Vascular Flora of Central Florida. University Presses of Florida, Gainesville.