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Learn more about Geocarpon in the Geocarpon minimum 5-Year Review (2009).

Geocarpon (Geocarpon minimum)
Status: Threatened
Listed: June 16, 1987

For questions regarding the Geocarpon in Arkansas, please contact Jason Phillips at jason_phillips@fws.gov or 870-347-1617.

Species Information:
Geocarpon is a tiny inconspicuous annual, ranging in size from 0.4 1.6 inches. It is usually only easily visible for three to six weeks during the spring, when it flowers and fruits. The factors affecting the timing and success of germination are not fully understood, although many researchers suggest that temperature and weather conditions are the two primary factors. A high variability in the number of observed plants between years indicates that seeds remain viable for at least several years.

Geocarpon minimum is the only species in the Geocarpon genus. Researchers at the Missouri Botanical Gardens have begun studying genetic variability between geographically isolated populations and populations that occur in differing habitats.

Habitat Summary:
Geocarpon prefers the edges of saline (salt) barrens in grasslands called "slicks" or "slickspots." The site containing the largest known population in Arkansas (Warren Prairie) is owned and managed by the Arkansas Natural Heritage Commission (ANHC) in cooperation with The Nature Conservancy.

Why is it Threatened?
Vegetation encroachment, cattle grazing, and landscape alteration are the main threats. Loss of the required microhabitats is assumed to stem from the human suppression and changing of natural disturbances like fire, hydrology, and native large mammals. Without these disturbances, other native or invasive plants can more easily compete with and shade Geocarpon populations.

S In Arkansas, the ANHC recognizes four Geocarpon populations containing 33 subpopulations. A total of 23 out of 33 subpopulations in Arkansas are on public land or land owned by a private conservation group.

Although Geocarpon has a vastly reduced distribution due to changes in climate and habitat, the majority of remaining populations are stable and/or growing. About half of the known populations, including many with the largest populations, are protected by public ownership or private protective agreements.

Learn more about Geocarpon recovery efforts in the Geocarpon minimum 5-Year Review (2009).

Range in Arkansas:


Arkansas Field Office
110 S. Amity Road
Suite 300
Conway, AR 72032

501/513 4470 (v)
501/513 4480 (f)

Last Updated: December 30, 2015

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