The following Participating Institutions are custodians for this species in the CPC National Collection:
The Holden Arboretum
Missouri Botanical Garden
Cincinnati Zoo & Botanical Garden
The conservation of Trifolium stoloniferum is fully sponsored.
Kimberlie McCue, Ph.D. contributed to this Plant Profile.
From 1940 until 1985, running buffalo clover was thought to be extinct. Then two populations were rediscovered in West Virginia. Since that initial rediscovery, a number of populations have been found in five of the eight states of this species' original distribution.
A story of the re-discovery of this plant in the state of Missouri is particularly interesting. In 1989, this species was still considered extirpated from the state of Missouri: the plant could not be found at any of its historical locations. The Missouri Department of Conservation began to consider re-introduction of the species to some of the historical locations.
In 1990, a botanist working for the Missouri Department of Conservation had a load of topsoil delivered to his house to use for gardening. Before he was able to spread the soil, seeds in the topsoil began to germinate, and he allowed them to grow into identifiable plants. To his, and everyone's, amazement, several plants of running buffalo clover appeared there. The source area of that topsoil delivery was searched, but no plants were found. However, these newly discovered plants were propagated and used in Missouri re-introduction efforts.
In 1994, a naturally-occurring population of this species was discovered on private land in SE Missouri. This was the first natural site of the population known to exist in the state since 1907, except for the plants found in the 1990 load of topsoil. Genetic testing showed that plants from the 1994-discovered site and plants from the 1990 load of topsoil were genetically similar to each other, as well as genetically distinct from plants in other states. This was a great discovery and re-introductions continue in that state, using plants from Missouri stock.
This clover is similar to other native and introduced clovers in the Midwest. It does have distinguishing characteristics, though, not the least of which give the plant both its scientific and common name. The scientific name Trifolium (three leaves) stoloniferum (having stolons) is very descriptive in and of itself. The common name of RUNNING BUFFALO CLOVER came from the fact that stolons, or RUNNERS, extend from the base of this plant's stems. These runners are able to root and expand the size of an originally small clump of clover into one or more larger ones. This plant is thought to have been more widespread before the loss of bison from its habitat. Bison are thought to have played a role in maintaining the open habitat that this species requires for survival.
Flowers appear on a stem with a pair of leaflets (unique to this species), and are white tinged with purple. These flowers appear from May through July. The three leaflets of the clover lack the arrow-shaped "watermarks" that are typical of other clovers. (West Virginia Department of Natural Resources 1998)
Distribution & Occurrence
- West Virginia
Partly sunny locations with moist, fertile soils that have been exposed to long-term moderate disturbance patterns (including mowing, trampling, and grazing). This plant is often found in the ecotone between open forest and prairie.
| Apparently extirpated from AR, IL, KS.
Extant populations number 2 in Indiana, 23 in Kentucky, 3 in Missouri, 12 in Ohio, and 25 in West Virginia. (all numbers are estimates and subject to change). (USFWS 1989)
Conservation, Ecology & Research
This is the only clover to date that has been found to have no rhizobial association. Rhizobium nodulate the roots of plants, increasing nitrogen availability to the plant. It is unknown whether a suitable rhizobial associate exists and is no longer able to infect running buffalo clover, 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.
Competition from non-native plants
Loss of pollinators
Susceptibility to new viruses
Small population size may lead to inbreeding depression
Campbell et al. (1988) recount historical sightings of this species, and outlines protocols for propagation of this species. NatureServe (2001) also discusses more extensive work being done on the propagation of the species.
NatureServe and the Campbell paper also hypothesize possible explanations for the apparent drastic decline of running buffalo clover early in the 20th century.
As discussed in the life history section of the recovery plan for this species, some research has been done on pathogens that attack this and other clover species, as well as potential treatments for these various pathogens. This section of the recovery plan also discusses the unusual lack of a rhizobial association for this species (see the Ecological Relationship section for more information on this).
Material from wild populations has been cultivated to ensure that the genetic material represented by the species isn't lost. Reintroduction efforts using material that is representative of the reintroduction site are being carried out at historic locations of the species in many states.
A 1998 report issued by then Secretary of the Interior Bruce Babbitt said many species were being considered for downlisting, and Trifolium stoloniferum was among those species. The reasons cited for downlisting by the Fish and Wildlife Service were that at the time of listing the population and distribution of this plant were underestimated, and that many of the recovery goals had been met.
Seeds from wild populations have been germinated & placed into cultivation, and the US Department of Agriculture is conducting horticultural studies on Trifolium stoloniferum because of its potential economic value (USFWS Species Account 1990).
The Missouri Department of Conservation has created a document that outlines Best Management Practices for this plant. Its purpose is to provide guidance to groups and individuals that want to protect this plant. This document outlines management activities that maintain open woodland habitat in the areas of Running Buffalo Clover. This includes allowing disturbances such as prescribed fire and grazing to continue in order to maintain optimal habitat for the species. (Missouri Department of Conservation 2000)
Assess potential for using grazing and/or fire as a tool to imitate presettlement disturbance conditions.
Determine if the species had a rhizobial association in the past (examine old herbarium specimens for nitrogen-fixing nodules), and if the current lack of a rhizobial association has an effect on the long-term viability of the species.
Baskin, J.M.; Baskin, C.C.; Jones, R.L. The Vegetation and Flora of Kentucky. A Symposium Sponsored by the Kentucky Academy of Science; November 22, 1986; Lexington, Kentucky. 1987. Kentucky Native Plant Society, Department of Biological Sciences, Eastern