It is found on coastal and inland sand ridges and is characterized by an evergreen xeromorphic plant community dominated by shrubs and dwarf oaks.

Lake Wales Ridge National Wildlife Refuge also holds a high proportion of remaining scrub habitat, while the Archbold Biological Station near Lake Placid contains about 20 km2 (7.7 sq mi) of scrub habitat and sponsors biological research on it.

[13] Florida scrub was probably first recognized as a distinct community by Charles Vignoles in 1823, although several naturalists working in the middle of the 19th century still did not do so.

[15] Marjorie Kinnan Rawlings described the edge of the Big Scrub as "a vast wall, keeping out the timid and the alien.

"[16] Webber states that at the end of the 19th century a natural firebreak separated scrubs from high pine land.

Webber observed that in 1935 the natural firebreaks seemed to be weakening, which he attributed to the encroachment of human civilization on the areas where scrubs are found.

Longleaf pine sandhill communities experience frequent (typically one to ten year intervals), low-intensity fires that primarily burn grass and other understory plants.

Fires that occur more frequently than 15 years in scrub can prevent regrowth of sand pines and shrubs (oaks, rosemary, etc.

Along the coasts, scrubs are bordered by the Atlantic Ocean or Gulf of Mexico, and often by inlets, rivers, and swamps.

Many seedlings of sand pines (6 to 8 inches (150 to 200 mm) high), and of other plants typical of the scrub community, were growing under the oak canopy.

The crowded conditions of the early stage of recovery leads to the death (thinning out) of many individual plants, and after a few years the typical scrub community is established.

[7] Plants that are endemic to scrub and "scrubby" communities in Florida[b] and that are listed as endangered by the United States Fish and Wildlife Service (USFWS) include: Asimina tetramera (four-petal pawpaw), Chionanthus pygmaeus (pygmy fringetree), Cladonia perforata (Florida perforate cladonia, Florida perforate reindeer lichen), Conradina brevifolia (short-leaved false rosemary), Conradina etonia (Etonia rosemary), Crotalaria avonensis (Avon Park rattlebox, Avon Park harebells, Avon Park rabbit-bells), Dicerandra christmanii (Garrett's mint, yellow scrub balm, Lake Wales balm), Dicerandra cornutissima (longspurred mint, longspurred balm, Robin's mint) Dicerandra frutescens (scrub mint or scrub balm), Dicerandra immaculata (Lakela's mint, Olga's mint, spotless balm), Eryngium cuneifolium (wedgeleaf eryngo, wedge-leaved button-snakeroot, snakeroot), Hypericum cumulicola (Highlands scrub hypericum, Highlands scrub St. John's wort), Liatris ohlingerae (Florida blazing star, Florida gayfeather, scrub blazing star,sandtorch), Lupinus aridorum (scrub lupine), Nolina brittoniana (Britton's beargrass), Senega lewtonii (syn.

Eriogonum floridanum) (scrub buckwheat), and Paronychia chartacea (papery Whitlow-wort, paper nailwort).

[28] Plants that are endemic to scrub and "scrubby" communities in Florida[b] and that are listed as threatened by the State of Florida (but not by the USFWS) include: Conradina grandiflora (largeflower false rosemary, large-flowered rosemary), Garberia heterophylla (garberia, Garber's scrub starts), Lechea cernua (nodding pinweed), and Polygonum smallianum (syn.

F. penneri, the oldest described species, has been found only in scrubs on the Lake Wales Ridge in Polk and Highlands counties.

Melanoplus indicifer, the east coast scrub grasshopper, has been found only on the Atlantic Coastal Ridge in Palm Beach County.

[33] The scarab beetles Serica frosti and Anomala eximia have been found only at the Archbold Biological Station in Highlands County.

The earth-boring scarab beetle Mycotrupes pedester has been found in Charlotte, DeSoto, and Lee counties.

Peltotrupes youngi, Young's deep digger scarab, has been found on the Mount Dora Ridge in Marion and Putnum counties.

[35] At least two dung beetles are endemic to the Florida scrub: Onthophagus aciculatulus has been found only at the Archbold Biological Station, and Ataenius saramari has been found on the Mount Dora Ridge and Sumter Uplands in Marion County, on the Atlantic Coastal Ridge in Martin and St. Lucie counties, near St.

[36] The wasp Dasymutilla archboldi has been found on the Lake Wales Ridge in Highlands and Polk counties.

megacarpus), flag-pawpaw (Asimina obovata), silk bay (Persea humilis), Adam's needle (Yucca filamentosa), and eastern prickly pear (Opuntia humifusa).

[44] Scrub communities on the peninsula coasts are found on dune systems associated with the Pamlico and Silver Bluff terraces of the Pleistocene period.

[c] Peninsular coastal scrubs are found on the east (Atlantic) coast of Florida as far north as St. Johns County, and were formerly found as far south as northern Broward County, although the southernmost scrubs on the east coast have been lost to urban development.

The sand pines of the Florida peninsula and of the panhandle coast differ enough to be classified into two varieties or races, Pinus clausa var.

[57] They are dominated by scrub oaks, saw palmetto, and several plants in the Ericaceae family, including rusty staggerbush, poor grub, feterbush lyonia, and tarflower.

[58] The World Wildlife Federation formerly classified "sand pine scrub" as a temperate coniferous forest ecoregion.

[62] Scrubby flatwoods has been defined as scrubs without a sand pine canopy that are dominated by saw palmettos, evergreen oaks, rusty lyonia, or Florida rosemary.

[64] Scrubby flatwoods occur widely in Florida, but are more common in the southern part of the peninsula, where they are subject to a subtropical climate.

Scrubby flatwoods from which fire is excluded are eventually invaded by sand pine and associated scrub shrubs.