Salicornia rubra A. Nels.
Salicornia europaea ssp. rubra
Basis for Listing
This succulent halophyte is characteristic of salt flats and the margins of alkaline lakes in arid regions of the West. The range of Salicornia rubra is relatively widespread, but because of its specialized habitat its distribution is local and sporadic. The occurrence of S. rubra in Minnesota seems incongruous because its habitat is not widely known to occur in the state. Such habitats do exist at the western edge of Minnesota, but they have always been uncommon and have now been largely eliminated by agricultural activities.
Among Minnesota's flora, S. rubra is distinguished by its pale green color, succulent jointed stem, and skeleton-like appearance. At maturity the stem turns ruby red, creating the look of a red carpet around pond margins where it occurs. However, positive identification relies on technical characters of the flowers, which are difficult to observe in the field and are not well preserved in dried specimens. Fruiting spikes occur in the upper joints and form slender cylinders that turn red at maturity. There are 3 flowers in a triangular arrangement at each joint of the fruiting spike. Flowers are minute and enclosed within the fleshy calyx that is sunk into a hollow of the fleshy stem. Scales are broadly triangular, blunt or subacute; the middle one is the highest and usually reaches the tip of the joint. Leaves are dark reddish-green, triangular, scale-like, appressed, opposite, and attached at each stem node. The fruit is a small, flattened seed covered with minute hairs and enclosed in the spongy calyx (Vance 1984; Nelson 1992).
Salicornia rubra shows a preference for salt flats, alkaline depressions, exposed shores of alkaline lakes, and saline swales. These habitats are found in western Minnesota where the climate is more arid. When evaporation at a site exceeds inflow of water, soluble salts and exchangeable sodium may accumulate, resulting in alkaline or saline soils. These salts or sodium can be found naturally in the soil, in soluble fertilizer salts, in stream water, lake water, or irrigation water. Associated plant species that are also tolerant of these extreme conditions include Atriplex patula (spearscale), Distichlis spicata var. stricta (salt grass), Hordeum jubatum (foxtail barley), Puccinellia nuttalliana (Nuttall's alkali grass), and Suaeda calceoliformis (seablite). Suitable habitats receive full sunlight, and are sparsely vegetated.
Biology / Life History
Salicornia rubra is an annual herb. It competes favorably on saline and alkaline soils. As a wetland dries or water levels recede, the seeds of this species will germinate in the exposed salt or alkali-encrusted silt.
Conservation / Management
Because native habitats on saline and alkaline soils that S. rubra prefers have been largely eliminated by agricultural activities, it is very important to protect any remaining habitats from degradation. Wetland protection laws that prevent draining or filling are vital in this regard. Further research is also needed on the habitat, life history, population trends, beneficial management practices, reproductive biology, ecology, and population demographics of this species.
Conservation Efforts in Minnesota
Salicornia rubra was discovered at four locations in Kittson County between 1991 and 2004. The only verified record outside of Kittson County is from the Salt Lake Wildlife Management Area in Lac Qui Parle County. The population there is large, well protected, and presumably viable. Other than the public land protection afforded at this site, no specific conservation efforts have been undertaken on behalf of this rare species.
References and Additional Information
Nelson, R. A. 1992. Handbook of Rocky Mountain plants. Fourth Edition. Roberts Rinehart Publishers, Niwot, Colorado. 444 pp. + illustrations + keys.
Vance, F. R., J. R. Jowsey, J. S. McLean, and F.A. Switzer. 1984. Wildflowers of the Northern Great Plains. University of Minnesota Press, Minneapolis, Minnesota. 382 pp.