''Trifolium stoloniferum'', the running buffalo clover,
is an
endangered species
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...
of perennial
clover
Clover or trefoil are common names for plants of the genus ''Trifolium'' (from Latin ''tres'' 'three' + ''folium'' 'leaf'), consisting of about 300 species of flowering plants in the legume or pea family Fabaceae originating in Europe. The genus ...
native to the eastern and midwestern
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
. From 1940 to 1985 it was believed to be extinct until two populations were discovered in West Virginia. Since then, more populations have been found in the US but it still remains one of the most imperiled plants in North America.
Description
This plant has erect, unbranched flowering stems, typically tall. The apex of the stem is topped by a round
flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...
head, subtended by two
leaves
A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...
. These apical leaves are typically larger than those found on stems without flowers. The flower heads are white, sometimes tinged with purple, and 2–2.5 cm diameter.
Like other clovers, running buffalo clover has leaves divided into three leaflets. It sends out long creeping runners (stolons) from its base, which grow along the ground and take root. The stems and leaves are hairless. It flowers from mid-May to June and fruits in July.
Habitat
The original habitat of this plant is believed to have been areas of rich
soil
Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former te ...
s in open areas among forests and prairies. Grazing
bison
Bison are large bovines in the genus ''Bison'' (Greek: "wild ox" (bison)) within the tribe Bovini. Two extant and numerous extinct species are recognised.
Of the two surviving species, the American bison, ''B. bison'', found only in North Ame ...
probably maintained these open areas while migrating along established trails. Running buffalo clover has current populations in West Virginia, Ohio, Kentucky, Indiana, Pennsylvania and Missouri. There are also historical reports from Illinois, Kansas, and Arkansas.
Remaining running buffalo clover populations are generally small and sporadically located. It is most often rediscovered in lightly shaded woodlands along streams, but some have also been found in lawns of old home sites and cemeteries.
Threats
Historical records show that running buffalo clover was once abundant in certain parts of its range, but it rapidly disappeared upon pioneer settlement. The reasons for this plant's decline are not known entirely, but they are believed to be directly related to the disappearance of large
herbivore
A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...
s from the plant's habitat. This species appears to have been dependent upon the woodland disturbance created by large animals, especially the bison. Many of the species' old records were in proximity to bison licks and trails. Other causes may include competition from introduced species and habitat loss.
Running buffalo clover is also the only known species of ''Trifolium'' that has no apparent
rhizobial association. Rhizobia typically nodulate the roots of ''Trifolium'', increasing nitrogen availability to the plant. It is unknown whether ''Trifolium stoloniferum'' has lost the ability to associate with rhizobia due to the high nitrogen environment associated with Bison, or if the rhizobial associate is extinct due to either the decline of the clover or from competition with rhizobia that was introduced with exotic clovers.
References
U.S. Fish and Wildlife Service Division of Endangered SpeciesEndangered Species Guidesheet - Running Buffalo Clover
External links
USDA Plants Profile for ''Trifolium stoloniferum'' (running buffalo clover)National Collection of Imperiled Plants profile of ''Trifolium stoloniferum''
{{Taxonbar, from=Q1953441
stoloniferum
Endemic flora of the United States
Flora of Arkansas
Flora of Illinois
Flora of Indiana
Flora of Kentucky
Flora of Ohio
Flora of Missouri
Flora of West Virginia
Taxa named by Gotthilf Heinrich Ernst Muhlenberg