|Guthrie's ground-plum, limestone glade milkvetch, Pyne's Ground Plum, Pyne's ground-plum|
|Barneby & Bridges|
|Kimberlie McCue, Ph.D.|
The following Participating Institutions are custodians for this species in the CPC National Collection:
Missouri Botanical Garden
The conservation of Astragalus bibullatus is fully sponsored.
Kimberlie McCue, Ph.D. contributed to this Plant Profile.
Pyne's ground-plum is a beautiful legume that is endemic to the Central Basin of Tennessee. First described in 1987, the plant is found only in a cedar glade habitat (Barneby and Bridges 1987). The ground-plum gets its name from the fruits produced in late May to early June. While the lavender flowers are borne on upright stalks, as the fruits develop the stalks bend back towards the ground. The fruits turn a reddish orange color and appear larger than one would expect, given the overall size of the plant.
Distribution & Occurrence
Pyne's ground-plum is endemic to the cedar glades of middle Tennessee. All sites are associated with thin-bedded, fossiliferous Lebanon limestone outcroppings that support the unique cedar glade communities found in Tennessee's central basin (USFWS 1991).
Common associates include Juniperus virginiana, Pediomelum subacaule, Hypericum sphaerocarpum, Manfreda virginica, Glandularia canadensis, and Onosmodium molle (USFWS 1991).
|There are three known wild populations (USFWS 1991).|
Conservation, Ecology & Research
Rabbit herbivory and all-terrain vehicles (ATV's) also pose significant threat
Workers at Missouri Botanical Garden have been working with this species for a number of years, and have established reliable protocols for propagating A. bibullatus from seed. (McCue et al. 2001)
Genetic studies using allozymes demonstrated that higher genetic diversity is found in the resident seed bank for this population than in vegetative populations, and determined that seeds in the uppermost layer of the seed bank showed increased inbreeding and decreased relative levels of gene flow. (Morris et al. 2002)
The Tennessee Department of Environment and Conservation is monitoring all known sites.
Pyne, M.; Gay, M.; Shea, A. 1995. Guide to rare plants - Tennessee Division of Forestry District 5. Nashville: Tennessee Dept. Agriculture, Division of Forestry.