Botrypus virginianus

Botrypus virginianus
Conservation status
Secure  (NatureServe)
Scientific classification
Kingdom:	Plantae
Division:	Ophioglossophyta
Class:	Ophioglossopsida
Order:	Ophioglossales
Family:	Ophioglossaceae[1][2]
Genus:	Botrypus
Species:	B. virginianus
Binomial name
Botrypus virginianus (L.) Michx. 1803
Synonyms
Botrychium virginianum (L.) Sw. 1801 Japanobotrychium virginianum (L.) M.Nishida 1958

Spore-producing frond of Botrypus virginianus

Botrypus virginianus, sometimes called rattlesnake fern,^[3] is a low-growing herb in the Ophioglossales, commonly a foot high or smaller. The plant is ternately branched and the leaves feel soft. The stem is bicolor, being pinkish or light tan at the base but greenish nearer the branches or leaves.

This is a wide-ranging species. It abounds in many parts of the United States, in the mountains of Mexico, in Australia, in some parts of Asia, as the Himalaya Mountains, and is found also in Norway, in the Karelia region of Finland and Russia, and around Gulf of Bothnia, although in no other part of Europe. It is large and succulent and is boiled and eaten in the Himalayas, etc. It is called Rattlesnake Fern in some parts of North America, from its growing in places where rattlesnakes are also found.

Recent research has determined that the mitochondria are genetic chimera. DNA from some member of the Santalales, possibly a species of mistletoe, has transferred to the mitochondrial genome of this species of fern.^[4] It is believed that this transfer may have helped to enable this plant's cosmopolitan global distribution.

This plant has long been included in the genus Botrychium, but is unique within the genus because of chromosome number and other signatures, including the inclusion of presumed mistletoe dna within its mitochondria. Recent research has established that this plant is sister to all other Botrychioid plants, including both the genus Botrychium sensu strictu, and the genus Sceptridium, with the exception of a single known species, previously included in Botrypus, which is B. strictus. That plant was shown to be sister to all other Botrychioids, including B. virginianus, so must be segregated in its own genus.^[5]

This fern has been used medicinally. In India it is still used to treat dysentery.^[6]

References

1. Botrychium Tropicos.org. Missouri Botanical Garden. 16 Jan 2012
2. Christenhusz, Maarten J. M.; Zhang, Xian-Chun; Schneider, Harald (2011). "A linear sequence of extant families and genera of lycophytes and ferns" (PDF). Phytotaxa 19: 7–54.
3. "Botrychium virginianum". Natural Resources Conservation Service PLANTS Database. USDA. Retrieved 17 Jan 2011.
4. Davis, C. C., et al. 2005. Gene transfer from a parasitic flowering plant to a fern. Proc. R. Soc. B 272, 2237–2242.
5. Hauk, Warren D.; Parks, Clifford R.; Chase, Mark W. (2003). "Phylogenetic studies of Ophioglossaceae: evidence from rbcL and trnL-F plastid DNA sequences and morphology". Molecular Phylogenetics and Evolution 28 (1): 131–151. doi:10.1016/S1055-7903(03)00032-0. ISSN 1055-7903.
6. Ethnobotanical Leaflets