Peter's Mountain Mallow

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Peter's Mountain Mallow

Iliamna corei

ListedMay 12, 1986
FamilyMalvaceae (Mallow)
DescriptionPerennial with large rose or pink flowers.
HabitatSandstone outcrops.
ThreatsCompetition with introduced plants; poor reproduction.


Peter's Mountain mallow, Iliamna corei, is a perennial, up to 3 ft (1 m) tall, resembling a small hollyhock. Terminal clusters of odorless rose or pink flowers, each 2 in (5 cm) across, bloom in late July and August. The plant spreads through its rhizome, forming clumps of stems that are identical clones.

A closely related mallow, I. remota, found in Virginia, Indiana, and Illinois, is currently a candidate for federal listing.


This mallow grows only on Peters Mountain in western Virginia, where it is found in full sun in soil-filled pockets and crevices of an exposed sandstone outcrop. Surrounding vegetation is mixed pine and hardwood forest.


This species was first discovered on Peters Mountain (in Giles County, Virginia), above the narrows of the New River and has been found nowhere else. It was discovered in 1927, and has declined from an estimated 50 plants to its current levels.

In 1962, 40 clumps of plants with one to 15 plants in each clump were surveyed. These were scattered across no more than a tenth of an acre. The counting of clumps, stems, or plants has not been uniform over the years, but botanists agree that the population has declined drastically. In September 1985, only five plants and 32 stems were observed. A prolonged drought in recent years has further weakened the population. By the time the species recovery plan was published by the U. S. Fish and Wildlife Service (FWS) in 1990, the species was described as having only four remaining individuals in its single known population; the plant, however, is also in cultivation at the Virginia Polytechnic Institute and State University's experimental gardens in Blacksburg and at the North Carolina Botanical Garden in Chapel Hill. A highly successful seed collection and germination program has resulted in the production of thousands of additional seeds, virtually guaranteeing the survival of the species.


A hiking trail was built through the center of the population in the 1960s, destroying many plants. Fortunately, this trail is no longer in use. Growth of the forest canopy, caused in large part by fire suppression, has been a major factor in shading out much of the mallow population. Another threat appears to be competition from an introduced species, the weedy Canadian leafcup (Polymnia canadensis ), which now dominates the site. Because of the small number of surviving plants, their lack of vigor, and low reproduction, the species is very vulnerable.

In addition, browsing by wild animals is a threat. In 1987 a feral goat browsed all of the plant stems to within 12 in (30 cm) of the ground. In 1987 and 1988, a total of 16 stems were cut, apparently for collection. In 1986, all plants were fenced with chicken wire cages to prevent browsing by deer, and competing trees and shrubs, as well as some of the canopy-shading plants, were removed.

Conservation and Recovery

The listing of the Peter's Mountain mallow focused the attention of the botanical community on the species' plight, and the Endangered Species Act provided a funding avenue for research and recovery. Botanists at Virginia Polytechnic Institute and State University began looking for viable seeds at the population site. By sifting painstakingly through samples of the leaf litter, they were able to find more than 95 mallow seeds. The next problem was to determine why these seeds were not germinating naturally. Botanists learned that the seeds had to be scarified (i.e., have the hard seed coat opened) in order to germinate. Nicking the seed coats with a razor blade permitted germination and the production of many healthy mallow plants. Later, these plants bore healthy fruits that, in turn, produced thousands of seeds.

This seed source has provided critical stock for studying the species' biology. For example, cross-pollination experiments revealed that the original plants were not producing seeds because the species is not self-compatiblethat is, the flowers must be pollinated by another individual to produce viable seed. Having an expanded seed source also permitted botanists to conduct germination studies. In an important discovery, they found that, under natural conditions, the seed coats were almost certainly broken by light fires. Thus, although wildfires had been seen as a potential threat to survival, it turns out that the suppression of wildfires had actually contributed to the species' decline.

Listing the Peter's Mountain mallow also provided impetus to preserving its ecosystem. This goal was accomplished in 1992 when the Nature Conservancy purchased the only known site. Now that the habitat is under protective private ownership and biologists have developed an understanding of many of the species' requirements, attention has shifted to the use of management tools, such as prescribed burning, to promote the species' recovery.

Following its acquisition of the Peters Mountain site, the Nature onservancy and biologists with the Virginia Natural Heritage Program began conducting limited spring burns to stimulate seed germination. The 1992 burn resulted in 12 mallow seedlings, four of which survived their first year. But the next year's success exceeded all expectations. Following the May 1993 burn, some 500 seedlings appeared in the 33-by-43-ft (10-by-13-m) test area. Even with a projected survival rate of only 20%, such successes signal a tremendous increase in the natural population, and move the Peter's Mountain mallow closer to the day when it will be a secure, self-sustaining member of its ecosystem.

The 1990 recovery plan from the FWS has as its goal the ultimate delisting of the species. Before the species is delisted, it would be downlisted to threatened, and such an action would take place when the natural population has reached carrying capacity and has been self-maintaining or expanding into new areas for at least five years. Other criteria for downlisting include a sufficient understanding (for management purposes) of the plant's life history, ecology, and population biology; the existence of an established and continuing management program; the permanent protection of the only known habitat, the small tract of land on which the single population grows; and the propagation of plants representing a variety of genotypes at a minimum of two plant-breeding facilities.

For removal of the plant from its threatened status (i.e., its delisting), the FWS would also require that studies indicate it is appropriate to establish new populations; that five additional populations be located or established; and that these new populations be protected and stable or expanding for at least five years.


U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
300 Westgate Center Dr.
Hadley, Massachusetts 01035-9589
Telephone: (413) 253-8200
Fax: (413) 253-8308


Keener, C. S., and J. W. Hardin. 1962. " Iliamna corei Revisited." Castanea 27: 176-178.

Sherff, E. D. 1949. "Miscellaneous Notes on Dicotyledonous Plants." American Journal of Botany 36: 499-511.

U. S. Fish and Wildlife Service. 1990. "Peter's Mountain Mallow Recovery Plan." U. S. Fish and Wildlife Service, Newton Corner, Mass.

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Peter's Mountain Mallow

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