Basis for Listing

Although this small perennial plant is common and widespread in the mountains of western North America, it also has a remarkable history in the Midwest and illustrates an extreme case in rare plant biology. Montia chamissoi (montia) is believed to be a relict of the Midwest’s Pleistocene flora that survived the most recent glacial advances in the unglaciated region or Driftless Area of southeastern Minnesota and adjacent parts of Iowa and Wisconsin. When the glaciers retreated, M. chamissoi was unable to find suitable habitat in the recently deglaciated territory and remained confined to its isolated refugium. All that survives of this long history is a single population in the Mississippi River valley in Winona County (The Blufflands Subsection). A similar example in Fayette County, Iowa is believed to have been extirpated in the 20th century. For this reason, M. chamissoi was listed as an endangered species in Minnesota in 1984.

  Description

Montia chamissoi is closely related to Claytonia spp. (spring beauty) but bears only a technical resemblance to members of that genus. The stem of M. chamissoi is prostrate to erect with several pair of opposite pale green leaves with rounded tips. Both the leaves and stems are semi-succulent. The inflorescence is a raceme of 2 or more small flowers. Each flower has 2 sepals, 5 distinct rose-colored petals, 5 stamens, and a 3-branched style. The fruit is a small 3-valved capsule, each with 3 tiny black seeds. This species also has distinctive filiform stolons that trail along the ground and have small bulblets at their tips.

  Habitat

The Minnesota population occurs on the west-facing exposure of a low, dripping sandstone cliff. The cliff forms the east bank of a small intermittent stream in a deciduous forest. The sandstone face is nearly vertical but retains a thin layer of mud in which M. chamissoi is shallowly rooted. This is a cool, moist, shaded habitat where there is little competition from other species. The few associated species include Impatiens capensis (spotted touch-me-not), Cystopteris bulbifera (bulblet fern), and liverworts.

  Biology / Life History

Montia chamissoi was discovered in Winona County by J. M. Holzinger in 1889. The single surviving population is apparently stable despite over-collecting and a series of natural disasters. The population currently consists of hundreds of shoots or ramets that arise vegetatively from annual stolons that root at the nodes and produce tiny tubers or bulblets at their tips. This particular mode of reproduction allows M. chamissoi to survive in its unstable habitat, which is continuously eroding and slipping into the stream below. The ability to quickly replace lost individuals and maintain its precarious position may account for the remarkable longevity of this population. Seeds are produced by insect-pollinated flowers. The seeds are apparently dispersed by small animals, possibly ants, that gather the seeds for the edible eliasome.

  Conservation / Management

The singular nature of the Minnesota population and its tenuous existence on the eroding stream bank make it very susceptible to disruption from natural causes. It is also vulnerable to human activities that could disrupt the constant flow of cold spring water that sustains the plants. It is critically important to maintain the tree canopy that shades the habitat and retards run-off during a rainstorm.

  Best Time to Search

The best time to search for Montia chamissoi is in June or July, when at its peak of development.

  Conservation Efforts in Minnesota

The single Minnesota site of this rare species is in private ownership and no known conservation actions have been undertaken on its behalf.

  Authors/Revisions

Welby R. Smith (MNDNR), 2020

(Note: all content ©MNDNR)

  References and Additional Information

Holzinger, J. M. 1901. The duration of Claytonia chamissoi Ledeb. Plant World 4:41-43.

Miller, J. M. 2003. Montia. Pages 485-488 in Flora of North America Editorial Committee, editors. Flora of North America north of Mexico. Volume 4. Oxford University Press, New York, New York.

Ownbey, G. B., and T. Morley. 1991. Vascular plants of Minnesota: a checklist and atlas. University of Minnesota Press, Minneapolis. 320 pp.

Rhoads, A. F., A. Newbold, R. H. Mellon, and R. E. Latham. 1985. Montia chamissoi rediscovered along the Delaware River in Wayne County, Pennsylvania. Bartonia 51:77.

Wherry, E. T. 1964. The most disjunct species in Pennsylvania. Bartonia 34:7.