Leucotrichum
Encyclopedia
Leucotrichum is a fern
genus
in the family
Polypodiaceae
. It is one of about 26 genera of grammitid
s, an unranked
clade
within Polypodiaceae. The name of the genus refers to the white hairs that are usually present on the underside of the frond
.
Leucotrichum was established in 2010 and has five species
. The type species
for the genus is Leucotrichum organense. Four of the species had been in Lellingeria
, and one, Leucotrichum mortonii, had been in the defunct genus Xiphopteris
.
Leucotrichum has a disjunct distribution
. Leucotrichum organense and Leucotrichum schenckii are endemic to the Atlantic moist forests
of coastal
southeastern Brazil
. Leucotrichum mortonii is known only from Cuba
and the Dominican Republic
. Leucotrichum pseudomitchellae occurs in Costa Rica
and Panama
. Leucotrichum mitchellae ranges
through Mexico
, Central America
, and the Caribbean
.
of DNA sequence
s of grammitids showed that a few species of Lellingeria
are not closely related to the others. They are sister to a clade
of 26 species which at that time were in the genus Terpsichore. This was confirmed six years later in another molecular phylogenetic study on the grammitids. In 2010, four species from Lellingeria and one from Xiphopteris were transferred to the new genus Leucotrichum. The clade of 26 species that is sister to Leucotrichum was named as a new genus, Alansmia, in 2011.
Fern
A fern is any one of a group of about 12,000 species of plants belonging to the botanical group known as Pteridophyta. Unlike mosses, they have xylem and phloem . They have stems, leaves, and roots like other vascular plants...
genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Polypodiaceae
Polypodiaceae
Polypodiaceae is a family of polypod ferns, which includes more than 60 genera divided into several tribes and containing around 1,000 species. Nearly all are epiphytes, but some are terrestrial.-Description:...
. It is one of about 26 genera of grammitid
Grammitid
The Grammitid ferns form a clade within Polypodiaceae....
s, an unranked
Taxonomic rank
In biological classification, rank is the level in a taxonomic hierarchy. Examples of taxonomic ranks are species, genus, family, and class. Each rank subsumes under it a number of less general categories...
clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
within Polypodiaceae. The name of the genus refers to the white hairs that are usually present on the underside of the frond
Frond
The term frond refers to a large, divided leaf. In both common usage and botanical nomenclature, the leaves of ferns are referred to as fronds and some botanists restrict the term to this group...
.
Leucotrichum was established in 2010 and has five species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
. The type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
for the genus is Leucotrichum organense. Four of the species had been in Lellingeria
Lellingeria
Lellingeria is a genus of ferns in the family Polypodiaceae. It is one of the grammitids, a clade within Polypodiaceae that has not been ranked as a subfamily or tribe because the phylogeny of Polypodiaceae is not well understood....
, and one, Leucotrichum mortonii, had been in the defunct genus Xiphopteris
Xiphopteris
Xiphopteris is a defunct genus of ferns in the family Polypodiaceae. The name is derived from two Greek words: xiphos, "sword", and pteris, "fern"....
.
Leucotrichum has a disjunct distribution
Disjunct distribution
In biology, a taxon with a disjunct distribution is one that has two or more groups that are related but widely separated from each other geographically...
. Leucotrichum organense and Leucotrichum schenckii are endemic to the Atlantic moist forests
Atlantic moist forests
The Atlantic moist forests, also known as the Atlantic coastal forests, are tropical moist evergreen forests, part of the Atlantic Forests complex of eastern Brazil. The Atlantic moist forests mostly lie within 80 km of the Atlantic coast. Restingas, coastal forests which grow on stabilized...
of coastal
Coast
A coastline or seashore is the area where land meets the sea or ocean. A precise line that can be called a coastline cannot be determined due to the dynamic nature of tides. The term "coastal zone" can be used instead, which is a spatial zone where interaction of the sea and land processes occurs...
southeastern Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
. Leucotrichum mortonii is known only from Cuba
Cuba
The Republic of Cuba is an island nation in the Caribbean. The nation of Cuba consists of the main island of Cuba, the Isla de la Juventud, and several archipelagos. Havana is the largest city in Cuba and the country's capital. Santiago de Cuba is the second largest city...
and the Dominican Republic
Dominican Republic
The Dominican Republic is a nation on the island of La Hispaniola, part of the Greater Antilles archipelago in the Caribbean region. The western third of the island is occupied by the nation of Haiti, making Hispaniola one of two Caribbean islands that are shared by two countries...
. Leucotrichum pseudomitchellae occurs in Costa Rica
Costa Rica
Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....
and Panama
Panama
Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...
. Leucotrichum mitchellae ranges
Range (biology)
In biology, the range or distribution of a species is the geographical area within which that species can be found. Within that range, dispersion is variation in local density.The term is often qualified:...
through Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
, and the Caribbean
Caribbean
The Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...
.
History
In 2004, a phylogenetic studyResearch
Research can be defined as the scientific search for knowledge, or as any systematic investigation, to establish novel facts, solve new or existing problems, prove new ideas, or develop new theories, usually using a scientific method...
of DNA sequence
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...
s of grammitids showed that a few species of Lellingeria
Lellingeria
Lellingeria is a genus of ferns in the family Polypodiaceae. It is one of the grammitids, a clade within Polypodiaceae that has not been ranked as a subfamily or tribe because the phylogeny of Polypodiaceae is not well understood....
are not closely related to the others. They are sister to a clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
of 26 species which at that time were in the genus Terpsichore. This was confirmed six years later in another molecular phylogenetic study on the grammitids. In 2010, four species from Lellingeria and one from Xiphopteris were transferred to the new genus Leucotrichum. The clade of 26 species that is sister to Leucotrichum was named as a new genus, Alansmia, in 2011.