Botrychium

Botrychium is a genus of ferns, seedless vascular plants in the family Ophioglossaceae.<ref name="Christenhusz_2011b">Template:Cite journal</ref> Botrychium species are known as moonworts. They are small, with fleshy roots, and reproduce by spores shed into the air. One part of the leaf, the trophophore, is sterile and fernlike; the other, the sporophore, 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 mycorrhizal fungi.

The circumscription of Botrychium is disputed between different authors; some botanists include the genera Botrypus and Sceptridium within Botrychium, while others treat them as distinct. The latter treatment is provisionally followed here.

Phylogeny

Phylogeny of Botrychium<ref>Template:Cite journal</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Template:Clade

Unassigned species:

• Template:Txil<ref>B. daucifolium Tropicos.org. Missouri Botanical Garden. 27 Dec 2011</ref> (thin-leaved moonwort)<ref>B. daucifolium Taiwan Plant Names, www.eFlora.org 27 Dec 2011</ref>
• Botrychium farrarii Legler & Popovich 2024
• Botrychium onondagense Underw. 1903
• Botrychium rubellum Stensvold & Farrar 2024
• Botrychium socorrense Template:Au<ref>B. socorrense Tropicos.org. Missouri Botanical Garden. 26 Dec 2011</ref> (Isla Socorro moonwort)
• Botrychium sutchuanense Chien & Chun 1959
• †Botrychium ternatopsis Kuzitchkina 1960
• Botrychium tolucaense Wagner & Mickel 2004

Conservation

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.<ref name="Johnson-Groh2002">Template:Cite journal</ref> 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.<ref>Template:Cite journal</ref> Finally, some species produce gemmae, a form of asexual propagation achieved by budding of the root.<ref name="Johnson-Groh2002" />

Juvenile and dormant sporophytes 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 genus Glomus, which supply most fixed carbon for growth and reproduction.<ref>Template:Cite journal</ref>

This mycorrhizal dependence has also made lab cultivation of moonworts difficult. Thus far, only germination of the gametophyte has been successful.

External links

• USDA Plants Profile for Botrychium (grapefern)
• Efloras.org: Flora of North America, treatment of genus Botrychium
• ITIS.gov: List of Botrychium species — with species links.