Rare Species Guide

  Basis for Listing

This small prairie fern was entirely unknown to science when it was first discovered on Frenchman's Bluff in Norman County in 1986. It was officially described as Botrychium gallicomontanum in 1991 (Farrar and Johnson-Groh 1991). As of 2021, it has only been found in two western Minnesota counties, Glacier National Park (Montana), and the Black Hills (South Dakota). The site in Norman County (Red River Prairie Subsection) consists of over 500 plants, and the site in Kittson County (Aspen Parklands Subsection) consists of less than 100 plants. Extensive searching in western Minnesota has failed to locate any additional sites. The two Minnesota sites supporting B. gallicomontanum are believed to be potentially vulnerable to a variety of threats, including natural stochastic events and incompatible land management. Research is underway to determine the species response to typical prairie management activities. Botrychium gallicomontanum was listed as an endangered species in Minnesota in 1996.

  Description

Many Botrychium (moonwort) species are difficult to distinguish from one another, and B. gallicomontanum is no exception. It closely resembles B. campestre (prairie moonwort), B. spathulatum (spatulate moonwort), and B. minganense (Mingan moonwort) but can be distinguished by leaf characteristics. In B. gallicomontanum, the space separating the pair of basal leaf segments from the leaf segments directly above is much greater than the spacing between the upper pairs of leaf segments. Other distinguishing leaf features are that B. gallicomontanum's leaf segments are more strongly ascending, lower leaf segments are less symmetrical, and the sterile frond is distinctly stalked (Farrar and Johnson-Groh 1991). In all cases, a specialist should be consulted to obtain a positive identification.

  Habitat

In Minnesota, B. gallicomontanum occurs on dry sandy to gravelly prairie (on all slope aspects) and in dense as well as sparse prairie vegetation.

  Biology / Life History

This rare fern produces one leaf a year, each with a sterile blade and a structurally reduced fertile blade that produces the spores. Spores are produced every year during the adult life of the plant, which is estimated to last up to 10 - 12 years. The spores are wind and gravity dispersed. Although they can potentially disperse great distances, the vast majority of spores disperse no more than 2 meters (7 ft.). Germinated spores of this fern may exist underground for some eight years or more as a parasitic gametophyte before emerging above ground as a sporophyte. This is the normal process of sexual reproduction in ferns. This species is one of only four known fern species that produce gemmae on the underground rhizome. Gemmae are small spherical structures that, when detached from the rhizome, can develop directly into a sporophyte, bypassing the gametophyte stage entirely. This is a process of vegetative reproduction.

  Conservation / Management

The continuing loss and degradation of native prairie habitat in Minnesota is likely the greatest threat to this species. The future of B. gallicomontanum may be dependent on active and appropriate management of the two sites where it is known to occur. The fact that it is not found on the heavily grazed pasture adjacent to Frenchman's Bluff suggests that grazing cattle on prairie remnants would damage or destroy the species. Herbicide application is a known serious threat. At one of the two sites that harbor B. gallicomontanum, 40%-80% of the plants were damaged by herbicides. This species is not found in the Quercus macrocarpa (bur oak) and Populus spp. (aspen) woodlands adjacent to Frenchman's Bluff, which suggests that carefully timed prescribed fire could be useful in maintaining the open grassland habitat that appears to favor this species. But poorly timed prescribed fire can adversely impact the population; no B. gallicomontanum plants were found in the year following a growing-season burn in 1987. The species did steadily increase in numbers over the next decade (Farrar and Johnson-Groh 1991). Prescribed burns should only be done during the dormant season. Since B. gallicomontanum emerges from the ground very early in the spring and senesces by August, the appropriate season for a prescribed burn would be in autumn.

  Best Time to Search

The best time to search for Botrychium gallicomontanum is from the first week in June to early July, when aboveground plant parts are most abundant.

  Conservation Efforts in Minnesota

This is a diminutive and obscure plant. University-level research continues on B. gallicomontanum and other moonworts, increasing the understanding of the ecology and genetics of the Botrychium genus. But the information is just emerging and still incomplete, necessitating further studies. Of the two sites where B. gallicomontanum occurs in Minnesota, one is in a State Park and the other on a Scientific and Natural Area. This presumably imparts a certain level of protection for this species, but management plans need to be designed with the needs of this species in mind. Ongoing documentation and assessment of this species' response to management approaches should inform the future conservation of B. gallicomontanum.

  Authors/Revisions

Welby R. Smith (MNDNR), 2020

(Note: all content ©MNDNR)

  References and Additional Information

Farrar, D. R. 2018. Moonwort (Botrychium) systematics [web application]. Ada Herbarium, Iowa State University, Ames. . Accessed 26 Feb 2019.

Farrar, D. R., and C. L. Johnson Groh. 1990. Subterranean sporophytic gemmae in moonwort ferns, Botrychium subgenus Botrychium. American Journal of Botany 77(9):1168-1175.

Farrar, D. R., and C. L. Johnson-Groh. 1991. A new prairie moonwort (Botrychium subgenus Botrychium) from northwestern Minnesota. American Fern Journal 81(1):1-6.

Smith, W. R. 2023. Ferns and lycophytes of Minnesota: the complete guide to species identification. University of Minnesota Press, Minneapolis. 368 pp.