Geocarpon (Geocarpon minimum)
Listed: June 16, 1987
For questions regarding the Geocarpon in Arkansas, please contact Jason Phillips at firstname.lastname@example.org or 870-347-1617.
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.
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.
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: