Botrychium is a genus offerns, seedlessvascular plants in the familyOphioglossaceae.[1]Botrychium species are known asmoonworts. They are small, with fleshyroots, and reproduce byspores shed into the air. One part of the leaf, the trophophore, is sterile and fernlike; the other, thesporophore, is fertile and carries the clusters of sporangia or spore cases. Some species only occasionally emerge above ground and gain most of their nourishment from an association with mycorrhizalfungi.
The circumscription ofBotrychium is disputed between different authors; some botanists include the generaBotrypus andSceptridium withinBotrychium, while others treat them as distinct. The latter treatment is provisionally followed here.
Moonworts can be found in many environments, including prairies, forests, and mountains. While some Botrychium species are quite rare, conservation efforts can be difficult. Determining the rarity of a species is complicated by the plants’ small leaves, which stand only 2-10 centimeters above the soil.[32] Even more of a challenge in obtaining an accurate population count is the genus's largely subterranean life cycle. The vast majority of any one population of moonworts actually exists below ground in banks consisting of several types of propagules. One type of propagule is the ungerminated spores, which must percolate through the soil beyond the reach of light in order to germinate. This presumably increases the probability that the spore will be in range of a mycorrhizal symbiont before it produces the tiny, roughly heart-shaped gametophyte, which also exists entirely below ground.[46] Finally, some species produce gemmae, a form of asexual propagation achieved by budding of the root.[32]
Juvenile and dormantsporophytes can also be hidden in the soil for long periods of time. Mature sporophytes do not necessarily produce a leaf annually; they can remain viable underground for up to 10 years without putting up a photosynthetic component. This feat is made possible by their dependence on symbiotic partnership with AM fungi of the genusGlomus, which supply most fixed carbon for growth and reproduction.[47]
This mycorrhizal dependence has also made lab cultivation of moonworts difficult. Thus far, only germination of the gametophyte has been successful.
^Muller, S. (1992). "The impact of a drought in spring on the sporulation of Botrychium matricariifolium (Retz) A. Br. in the Bitcherland (Northern Vosges, France)".Acta Oecologica.13:335–343.
^abcdJohnson-Groh, C. L.; Lee, J. (2002). "Phenology and demography of two species of Botrychium (Ophioglassaceae)".American Journal of Botany.89 (10):1624–1633.doi:10.3732/ajb.89.10.1624.PMID21665590.
^B. mormo Flora of North America, www.eFloras.org 26 Dec 2011
^B. pallidum Flora of North America, www.eFloras.org 26 Dec 2011
^B. daucifolium Tropicos.org. Missouri Botanical Garden. 27 Dec 2011
^B. daucifolium Taiwan Plant Names, www.eFlora.org 27 Dec 2011
^B. socorrense Tropicos.org. Missouri Botanical Garden. 26 Dec 2011
^Whittier, D (1973). "The effect of light and other factors on spore germination in Botrychium dissectum".Can J Bot.51 (10):1791–1794.Bibcode:1973CaJB...51.1791W.doi:10.1139/b73-230.
^Winther, J; Friedman, W (2007). "Arbuscular mycorrhizal symbionts in Botrychium (Ophioglossaceae)".Am J Bot.94 (7):1248–1255.doi:10.3732/ajb.94.7.1248.PMID21636490.
