Lyrate Bladderpod

Lesquerella lyrata

Description

The lyrate bladderpod (Lesquerella lyrata ), a member of the mustard family, is an annual that ranges from 4-12 in (10.2-30.5 cm) in height. Plants are shortly pubescent and usually branched near the base. The stem leaves are alternate, ovate to elliptic in shape, smooth or toothed on the margins, with prominent ear-like projections at the bases. The flowers are ascending on stalks 0.4-0.6 in (1-1.5 cm) long, with yellow petals 0.2-0.3 in (5.1-7.6 mm) in length. The fruits are globular and about 0.1 in (2.5 mm) long. This species is dormant in the summer, surviving as seeds. It germinates in the fall and overwinters as a rosette. Plants flower from March to April; they fruit and disperse seeds in late April and May.

Habitat

L. lyrata is a component of glade flora and occurs in association with limestone outcroppings. The terms "glade" and "cedar glade" refer to shallow-soiled, open areas that are sometimes surrounded by cedar woods. L. lyrata often occurs without associates; however, it may occur with Alabama gladecress, sandwort, stonecrop, and weedy species such as chickweed and false dandelion. Current populations are located primarily on gladelike areas that exhibit various degrees of disturbance, including unimproved pastures, cultivated/plowed fields, and roadsides. Most of the cedar glade endemics exhibit such weedy tendencies; however, none appear to spread far from their original glade habitat.

Distribution

Only two populations of L. lyrata are known to exist, with one each in Franklin and Colbert counties, Alabama. Each population consists of several sites located within a 0.25-0.5-mi radius (0.4-0.8-km radius) of one another. Population size varies, as with all annuals; however, at times, sites are reported to support hundreds to thousands of individuals.

Threats

This species occurs in disturbed glade areas, including cultivated fields and unimproved pastures. While the plant may survive under these conditions, populations may be impacted if plowing or herbicide treatment occurs in the spring prior to seed set and dispersal in mid-May. Populations located in pastures are enhanced by disturbance created from light grazing; however, heavy grazing could negatively impact plants by excessive soil compaction. Improvement of pastures with the introduction of forage grasses would eventually decimate populations due to competition. Mowing along the roadside rights-of-way aids the species in seed dispersal; however, mowing and herbicide application prior to seed set pose a threat.

The greatest threat to this species is its extreme vulnerability due to its limited range and small number of populations. Disturbance—natural and artificial—appears to be a key factor in the maintenance of L. lyrata. Active management of sites will be required to perpetuate this species. Under natural conditions, L. lyrata is an early successional species that colonizes shallow cedar glade soils and then slowly disappears as the soil layer becomes further developed. This species is a poor competitor and is eliminated by shade and competition from the invading perennials. Due to the continuing loss of cedar glades, the available habitat for L. lyrata is limited primarily to areas modified by human activity. Current populations have declined in recent years due to succession from a lack of management/disturbance.

Conservation and Recovery

Private landowners have been informed of the need to protect the species. Active management of sites will be required to perpetuate this species. The service will work with the Alabama Heritage Program to develop habitat protection plans for all sites.

Contacts

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
1875 Century Blvd., Suite 200
Atlanta, Georgia 30345
http://southeast.fws.gov/

Jackson Ecological Services Field Office
6578 Dogwood View Parkway, Suite A
Jackson, Mississippi 39213-7856
Telephone: (601) 965-4900
Fax: (601) 965-4340

References

Baskin, J. M., and C. C. Baskin. 1986. "Distribution and geographical/evolutionary relationships of cedar glade endemics in southeastern United States." pp. 138-154. In. P. Somers, ed., Symposium: Biota, ecology, and ecological history of cedar glades. ASB Bulletin 33.

Kral, R. 1983. A report on some rare, threatened, or endangered forest-related vascular plants of the South. Forest Service, U.S. Department of Agriculture. Tech. Pub. R8-TP2.

McDaniel, S. T. 1987. "Status report on Lesquerella lyrata. " U. S. Fish and Wildlife Service, Jackson, Mississippi.

Rollins, R. C., and E. A. Shaw. 1973. The Genus Lesquerella in North America. Harvard University Press, Cambridge.

Webb, D. H., and R. Kral. 1986. "Recent collections and status of Lesquerella lyrata Rollins." Sida 11: 347-351.