''Botrypus virginianus'', synonym ''Botrychium virginianum'', sometimes called rattlesnake fern is a species of

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wid ...

fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes exce ...

in the adders-tongue family. It is

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...

within the genus ''Botrypus'', meaning that it is the only species within the genus. It is called the rattlesnake fern in some parts of North America, due to its habit of growing in places where rattlesnakes are also found. Rattlesnake fern prefers to grow in rich, moist woods in dense shade and will not tolerate direct sunlight.

Description

It is a low growing species, typically being a foot high or smaller. The leaf emerges in the early spring and will senesce in late summer. The leaf is roughly triangularly shaped and 15–50 cm in size and held roughly parallel to the ground. The leaf is 3-4 times pinnately compound, brightly green colored, and feels soft to the touch. The stem is round and bicolor, being pinkish or light tan at the base but greenish nearer the branches or leaves. The diploid number is 184. Rattlesnake fern has separate fertile and sterile leaves, when present the sterile leaf arises halfway up the stalk and the fertile leaf exists at the tip. The spores are shed in late spring. Like other ferns rattlesnake fern undergoes alternation of generations and the form described in this article is the sporophyte. This fern has been used medicinally. In India it is still used to treat

dysentery Dysentery (UK pronunciation: , US: ), historically known as the bloody flux, is a type of gastroenteritis that results in bloody diarrhea. Other symptoms may include fever, abdominal pain, and a feeling of incomplete defecation. Complications ...

Taxonomy and genetics

Recent research has determined that the mitochondria are genetic

chimera Chimera, Chimaera, or Chimaira (Greek for " she-goat") originally referred to: * Chimera (mythology), a fire-breathing monster of Ancient Lycia said to combine parts from multiple animals * Mount Chimaera, a fire-spewing region of Lycia or Cilici ...

. DNA from some member of the

Santalales The Santalales are an order of flowering plants with a cosmopolitan distribution, but heavily concentrated in tropical and subtropical regions. It derives its name from its type genus ''Santalum'' (sandalwood). Mistletoe is the common name for a ...

, possibly a species of mistletoe, has transferred to the mitochondrial genome of this species of fern. It is believed that this transfer may have helped to enable this plant's cosmopolitan global distribution. This plant has traditionally been included in the genus '' Botrychium'' as the subgenus ''Osmundopteris'' (based on the species' superficial similarities to the genus ''Osmunda''), but was 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 stricto – rattlesnake fern, common grapefern''B. virginianum''
Flora of North America, www.eFloras.org 26 Dec 2011 – 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, so must be segregated in its own genus.

Distribution

This is a wide-ranging species. It abounds in many parts of the United States, in the mountains of

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

, in Australia, in some parts of

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...

, as the

Himalaya Mountains The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 100 ...

, and is found also in

Norway Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and the ...

, in the Karelia region of

Finland Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of B ...

and Russia, and around Gulf of Bothnia, although in no other part of

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...

. It is large and succulent and is boiled and eaten in the Himalayas.

References

{{Taxonbar, from1=Q2077686, from2=Q17258002, from3=Q21876049 Ophioglossaceae Ferns of Asia Ferns of the Americas Ferns of Europe Ferns of Mexico Ferns of the United States Flora of China Flora of East Himalaya Ferns of Australia Plants described in 1753 Taxa named by Carl Linnaeus Taxa named by André Michaux Monotypic fern genera