Lysimachia maritima (L.) Galasso, Banfi & Soldano
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Basis for Listing
Lysimachia maritima is most characteristic of coastal sea marshes, encircling the northern latitudes from Eurasia to North America. It also appears in inland alkaline or saline wetlands. Habitats of this type are quite limited in Minnesota, which explains, in part, why the species is rare here. There are two documented occurrences in Minnesota. One is a herbarium specimen collected in 1962 in an alkaline prairie wetland near Humboldt in Kittson County. The other is a specimen collected in 1992 in a similar habitat several miles away. The more recent record describes the plant as being common in one small area, but absent from similar habitats nearby. Most of the potential wetland habitat in Minnesota is in Kittson County, but some is scattered throughout three or four other northwestern counties. There has been a general decline in this habitat type throughout the region. The high demand for tillable land has resulted in the drainage of most of the alkaline or saline wetlands for conversion to crop production, in spite of their unsuitability for most agricultural purposes. Lysimachia maritima was originally listed as a special concern species in Minnesota in 1984, but given its extreme rarity, it was reclassified as endangered in 1996.
It is rather difficult to confuse L. maritima with any other species, particularly those found in the same habitat. It is a low, succulent herb that spreads by underground stems, often forming carpets on the surface. Its fleshy leaves are short, stalkless, and oblong to narrow. The white, pink, or purple flowers are tucked in the leaf junctions. Lacking petals, it is the 5 sepals that provide color (Great Plains Flora Association 1986).
In Minnesota, the preferred habitat of L. maritima is imperfectly known, but probably includes alkaline or saline soil in low meadows, prairies, dry streambeds, and lakeshores. Studies show that this species tolerates high salinity and long periods submerged under water. It prefers moist, sparsely vegetated soil in direct sunlight, and has particular moisture requirements; too little or too much moisture restricts its distribution (Brotherson and Barnes 1984; Great Plains Flora Association 1986).
Biology / Life History
Lysimachia maritima does produce seeds, but under stable environmental conditions it is known to spread rapidly by vegetative means. The plant dies back during the fall but not before producing rhizomes that are able to survive the winter. Conditions that damage the plants, such as flooding and strongly fluctuating temperatures, also trigger seed germination. Seeds seem to resist decay and are reported to be viable in the seed bank for 100 years (Hammer and Heseltine 1988).
Conservation / Management
Lysimachia maritima faces a direct threat from wetland destruction. Wetlands across the Midwestern grain-producing region of the United States have been drained, ditched, filled, and dredged. As wetlands have disappeared, so have the species that relied on them, including L. maritima. It is critical that wetlands receive protection and that wetland laws be enforced. Light cattle grazing for short periods apparently does little permanent harm to this species, and may, in some cases, favor it by reducing the more palatable competition. But continuous heavy grazing can damage or eliminate populations by trampling and soil compaction.
Conservation Efforts in Minnesota
The Minnesota Biological Survey has inventoried Kittson County and found only one site of L. maritima. However, a considerable amount of potential habitat remains to be searched. Botanists agree that further searches, if highly directed and focused, have a chance of finding this species again.
References and Additional Information
Brotherson, J. D., and S. J. Barnes. 1984. Habitat relationships of Glaux maritima in central Utah. The Great Basin Naturalist 44(2):299-309.
Cholewa, A. F. 2009. Lysimachia. Pages 308-318 in Flora of North America Editorial Committee, editors. Flora of North America north of Mexico. Volume 8. Oxford University Press, New York, New York.
Great Plains Flora Association. 1986. Flora of the Great Plains. University Press of Kansas, Lawrence, Kansas. 1,402 pp.
Hammer, U. T., and J. M. Heseltine. 1988. Aquatic macrophytes in saline lakes of the Canadian prairies. Hydrobiologica 158:101-116.
Jerling, L. 1988. Population dynamics of Glaux maritima (L.) along a distributional cline. Vegetation 74:161-70.