''Botrychium'' is a genus of
fern
The ferns (Polypodiopsida or Polypodiophyta) are a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. They differ from mosses by being vascular, i.e., having specialized tissue ...
s, seedless
vascular plant
Vascular plants (), also called tracheophytes (, ) or collectively tracheophyta (; ), are plants that have lignin, lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified Ti ...
s in the family
Ophioglossaceae
Ophioglossaceae, from Ancient Greek ὄφις (''óphis''), meaning "snake", and γλῶσσα (''glôssa''), meaning "tongue", also known as the adder's-tongue family, is a small family of ferns. In the Pteridophyte Phylogeny Group classificatio ...
.
''Botrychium'' species are known as moonworts. They are small, with fleshy
root
In vascular plants, the roots are the plant organ, organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often bel ...
s, and reproduce by
spore
In biology, a spore is a unit of sexual reproduction, sexual (in fungi) or asexual reproduction that may be adapted for biological dispersal, dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores fo ...
s 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
A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...
.
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''
Unassigned species:
* (thin-leaved moonwort)
* ''
Botrychium farrarii''
Legler & Popovich 2024
* ''
Botrychium onondagense''
Underw. 1903
* ''
Botrychium rubellum''
Stensvold & Farrar 2024
* ''
Botrychium socorrense'' (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.
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. Finally, some species produce gemmae, a form of asexual propagation achieved by budding of the root.
Juvenile and dormant
sporophyte
A sporophyte () is one of the two alternation of generations, alternating multicellular organism, multicellular phases in the biological life cycle, life cycles of plants and algae. It is a diploid multicellular organism which produces asexual Spo ...
s 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.
This mycorrhizal dependence has also made lab cultivation of moonworts difficult. Thus far, only germination of the gametophyte has been successful.
References
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''.
{{Authority control
Fern genera
Ferns of the Americas
Ferns of the United States
Taxa named by Olof Swartz