Rare Species Guide

 Lysimachia maritima    (L.) Galasso, Banfi & Soldano

Sea Milkwort 


MN Status:
endangered
Federal Status:
none
CITES:
none
USFS:
none

Group:
vascular plant
Class:
Dicotyledoneae
Order:
Primulales
Family:
Primulaceae
Life Form:
forb
Longevity:
perennial
Leaf Duration:
deciduous
Water Regime:
wetland
Soils:
sand, loam
Light:
full sun
Habitats:

(Mouse over a habitat for definition)


Best time to see:

 Foliage Flower Fruit 
Janspacer
spacer
spacerspacer
spacer
spacerspacer
spacer
spacer
Febspacer
spacer
spacerspacer
spacer
spacerspacer
spacer
spacer
Marspacer
spacer
spacerspacer
spacer
spacerspacer
spacer
spacer
Aprspacer
spacer
spacerspacer
spacer
spacerspacer
spacer
spacer
Mayspacer
spacer
spacerspacer
spacer
spacerspacer
spacer
spacer
Junspacer
spacer
spacerspacer
spacer
spacerspacer
spacer
spacer
Julspacer
spacer
spacerspacer
spacer
spacerspacer
spacer
spacer
Augspacer
spacer
spacerspacer
spacer
spacerspacer
spacer
spacer
Sepspacer
spacer
spacerspacer
spacer
spacerspacer
spacer
spacer
Octspacer
spacer
spacerspacer
spacer
spacerspacer
spacer
spacer
Novspacer
spacer
spacerspacer
spacer
spacerspacer
spacer
spacer
Decspacer
spacer
spacerspacer
spacer
spacerspacer
spacer
spacer
Minnesota range map
Map Interpretation
North American range map
Map Interpretation

  Synonyms

Glaux maritima

  Basis for Listing

Lysimachia maritima (sea milkwort) is most characteristic of coastal sea marshes, encircling the northern latitudes from Eurasia to North America. It also appears in isolated inland alkaline or saline wetlands. Habitats of this type are quite limited in Minnesota, which explains, in part, why the species is rare here. Recent record describes the plant as being common in one small remnant habitat but absent from similar habitats nearby. Most of the potential wetland habitat in Minnesota is in Kittson County, but some is scattered in three or four other western counties (Red River Prairie Subsection). 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.

  Description

It is rather difficult to confuse L. maritima with any other species, particularly those found in the same habitat. It is a low succulent perennial 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. The fruit is a capsule 2-3 mm (0.08-0.12 in.) across (Great Plains Flora Association 1986).

  Habitat

In Minnesota, the preferred habitat of L. maritima is imperfectly known but probably includes alkaline or saline soil in low meadows, seasonally wet prairies, periodically 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 reproduces primarily by vegetative means. This happens when small plantlets develop from buds at the nodes of underground rhizomes. The above-ground portions of the plants die back during the fall, but the buds are able to survive the winter. Seeds seem to resist decay and are reported to be viable in the seed bank for 100 years (Hammer and Heseltine 1988). Like most halophytic plant species, L. maritima possesses specialized mechanisms to cope with high concentrations of salt (sodium chloride) in the rooting zone of its habitat. This includes highly unusual salt glands on the leaf surfaces that secrete excess salt which would ordinarily be injurious to plant tissue (Rozema and Riphagen 1977).

  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 too 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.

  Best Time to Search

The best time to search for Lysimachia maritima is during the flowering period from mid-June through September.

  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.

  Authors/Revisions

Welby R. Smith (MNDNR), 2020

(Note: all content ©MNDNR)


Back to top