Lellingeria
Encyclopedia
Lellingeria is a genus
of fern
s in the family
Polypodiaceae
. It is one of the grammitid
s, a clade
within Polypodiaceae that has not been ranked
as a subfamily or tribe
because the phylogeny
of Polypodiaceae is not well understood.
Approximately 70 species
of Lellingeria are known. They are native
to tropical areas of Madagascar
, Africa
, the Americas
, and Pacific Islands
. None are known in cultivation. Lellingeria was named for the American
pteridologist David Lellinger.
in a study
published in 2010. These authors do not recognize some of the species that were included in the 1991 paper in which Lellingeria was established.
s. Rhizome
radially symmetrical or dorsiventral, with clathrate, usually blackish scales
that are attached across their entire base. Petiole
absent or much shorter than the lamina. Sterile portion of frond
shallowly to deeply pinnately divided. Fertile portion entire
to deeply pinnately divided. (A few species with fronds pinnate-pinnatifid
). Veins simple, free (not anastomosing
). Hydathode
s present. Sori round or elliptic, often slightly sunken, without paraphyses
.
) genus Grammitis
. In 2004, a phylogenetic study of DNA sequence
s of two chloroplast
gene
s showed that Lellingeria, as defined in 1991, was polyphyletic. This was confirmed six years later. In 2010, four species were removed from Lellingeria and combined with one species from the defunct genus Xiphopteris
to form the new genus Leucotrichum
. The remaining species of Lellingeria form a monophyletic genus that is sister to the genus Melpomene
.
as Leucotrichum, and because another two of these groups were not truly distinct, but intermixed. Lellingeria, as currently circumscribed
consists of two groups, one with about 20 species, and another with about 50. The smaller group is easily distinguished by morphological
characters, but the larger group is more diverse
. These two groups have not been formally named
as subgenera
or sections
within Lellingeria.
Lellingeria can be distinguished from Melpomene by the lack of seta
e, the presence of hairs on the rhizome, the sparse covering of very short hair on the upper surface of the rachis
or midrib, and by the sori, which are slightly sunken into the lamina.
When Lellingeria was first described in 1991, it was thought to always have a radially symmetrical rhizome, but it has since been learned that some of the species that belong in Lellingeria have a dorsiventral rhizome. The unequally forked hairs are almost always present, but they are not a synapomorphy
for Lellingeria.
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...
of fern
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...
s 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 the grammitid
Grammitid
The Grammitid ferns form a clade within Polypodiaceae....
s, 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...
within Polypodiaceae that has not been ranked
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...
as a subfamily or tribe
Tribe (biology)
In biology, a tribe is a taxonomic rank between family and genus. It is sometimes subdivided into subtribes.Some examples include the tribes: Canini, Acalypheae, Hominini, Bombini, and Antidesmeae.-See also:* Biological classification* Rank...
because the phylogeny
Phylogenetic tree
A phylogenetic tree or evolutionary tree is a branching diagram or "tree" showing the inferred evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical and/or genetic characteristics...
of Polypodiaceae is not well understood.
Approximately 70 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...
of Lellingeria are known. They are native
Indigenous (ecology)
In biogeography, a species is defined as native to a given region or ecosystem if its presence in that region is the result of only natural processes, with no human intervention. Every natural organism has its own natural range of distribution in which it is regarded as native...
to tropical areas of Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
, Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
, the Americas
Americas
The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...
, and Pacific Islands
Pacific Islands
The Pacific Islands comprise 20,000 to 30,000 islands in the Pacific Ocean. The islands are also sometimes collectively called Oceania, although Oceania is sometimes defined as also including Australasia and the Malay Archipelago....
. None are known in cultivation. Lellingeria was named for the American
American ethnicity
American ethnicity differs from United States nationality. An individual's nationality is American if he or she is a national of the United States of America. The circumstances under which a person is ethnically American are less clear....
pteridologist David Lellinger.
Species
The following is a list of those species that were sampledSample (material)
In general, a sample is a limited quantity of something which is intended to be similar to and represent a larger amount of that thing. The things could be countable objects such as individual items available as units for sale, or a material not countable as individual items. Samples of countable...
in a study
Research
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...
published in 2010. These authors do not recognize some of the species that were included in the 1991 paper in which Lellingeria was established.
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Description
Mostly epiphyteEpiphyte
An epiphyte is a plant that grows upon another plant non-parasitically or sometimes upon some other object , derives its moisture and nutrients from the air and rain and sometimes from debris accumulating around it, and is found in the temperate zone and in the...
s. Rhizome
Rhizome
In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...
radially symmetrical or dorsiventral, with clathrate, usually blackish scales
Trichome
Trichomes are fine outgrowths or appendages on plants and certain protists. These are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae.- Algal trichomes :...
that are attached across their entire base. Petiole
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
absent or much shorter than the lamina. Sterile portion of 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...
shallowly to deeply pinnately divided. Fertile portion entire
Leaf shape
In botany, leaf shape is characterised with the following terms :* Acicular : Slender and pointed, needle-like* Acuminate : Tapering to a long point...
to deeply pinnately divided. (A few species with fronds pinnate-pinnatifid
Pinnate
Pinnate is a term used to describe feather-like or multi-divided features arising from both sides of a common axis in plant or animal structures, and comes from the Latin word pinna meaning "feather", "wing", or "fin". A similar term is pectinate, which refers to a comb-like arrangement of parts...
). Veins simple, free (not anastomosing
Anastomosis
An anastomosis is the reconnection of two streams that previously branched out, such as blood vessels or leaf veins. The term is used in medicine, biology, mycology and geology....
). Hydathode
Hydathode
A hydathode is a type of secretory tissue in leaves, usually of Angiosperms, that secretes water through pores in the epidermis or margin of leaves, typically at the tip of a marginal tooth or serration. They probably evolved from modified stomata...
s present. Sori round or elliptic, often slightly sunken, without paraphyses
Paraphyses
Paraphyses are part of the fertile spore-bearing layer in certain fungi. More specifically, paraphyses are sterile filamentous hyphal end cells composing part of the hymenium of Ascomycota and Basidiomycota interspersed among either the asci or basidia respectively, and not sufficiently...
.
History
The genus Lellingeria was erected in 1991. At that time, it consisted of 52 species, three newly described, and 49 transferred from the artificial (unnaturalNature
Nature, in the broadest sense, is equivalent to the natural world, physical world, or material world. "Nature" refers to the phenomena of the physical world, and also to life in general...
) genus Grammitis
Grammitis
Grammitis is a genus of ferns in the family Polypodiaceae. It had formerly been placed in the family Grammitidaceae, but this family is no longer recognized by most authors because phylogenetic analyses of DNA sequences have shown that it is embedded in Polypodiaceae. The delimitation of...
. In 2004, a phylogenetic study 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 two chloroplast
Chloroplast
Chloroplasts are organelles found in plant cells and other eukaryotic organisms that conduct photosynthesis. Chloroplasts capture light energy to conserve free energy in the form of ATP and reduce NADP to NADPH through a complex set of processes called photosynthesis.Chloroplasts are green...
gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
s showed that Lellingeria, as defined in 1991, was polyphyletic. This was confirmed six years later. In 2010, four species were removed from Lellingeria and combined with one species from 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"....
to form the new genus Leucotrichum
Leucotrichum
Leucotrichum is a fern genus in the family Polypodiaceae. It is one of about 26 genera of grammitids, 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....
. The remaining species of Lellingeria form a monophyletic genus that is sister to the genus Melpomene
Melpomene
Melpomene , initially the Muse of Singing, she then became the Muse of Tragedy, for which she is best known now. Her name was derived from the Greek verb melpô or melpomai meaning "to celebrate with dance and song." She is often represented with a tragic mask and wearing the cothurnus, boots...
.
Taxonomy
When Lellingeria was established in 1991, thirty-five of its species were assigned to four species groups. This infra-generic classification did not hold up, because one of these groups had to be separatedSegregate (taxonomy)
In taxonomy, a segregate, or a segregate taxon is created when a taxon is split off, from another taxon. This other taxon will be better known, usually bigger, and will continue to exist, even after the segregate taxon has been split off...
as Leucotrichum, and because another two of these groups were not truly distinct, but intermixed. Lellingeria, as currently circumscribed
Circumscription (taxonomy)
In taxonomy, circumscription is the definition of the limits of a taxonomic group of organisms. One goal of taxonomy is to achieve a stable circumscription for every taxonomic group. Achieving stability can be simple or difficult....
consists of two groups, one with about 20 species, and another with about 50. The smaller group is easily distinguished by morphological
Plant morphology
Plant morphology or phytomorphology is the study of the physical form and external structure of plants. This is usually considered distinct from plant anatomy, which is the study of the internal structure of plants, especially at the microscopic level...
characters, but the larger group is more diverse
Biodiversity
Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...
. These two groups have not been formally named
Botanical name
A botanical name is a formal scientific name conforming to the International Code of Botanical Nomenclature and, if it concerns a plant cultigen, the additional cultivar and/or Group epithets must conform to the International Code of Nomenclature for Cultivated Plants...
as subgenera
Subgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...
or sections
Section (botany)
In botany, a section is a taxonomic rank below the genus, but above the species. The subgenus, if present, is higher than the section, and the rank of series, if present, is below the section. Sections are typically used to help organise very large genera, which may have hundreds of species...
within Lellingeria.
Lellingeria can be distinguished from Melpomene by the lack of seta
Seta
Seta is a biological term derived from the Latin word for "bristle". It refers to a number of different bristle- or hair-like structures on living organisms.-Animal setae:In zoology, most "setae" occur in invertebrates....
e, the presence of hairs on the rhizome, the sparse covering of very short hair on the upper surface of the rachis
Rachis
Rachis is a biological term for a main axis or "shaft".-In zoology:In vertebrates a rachis can refer to the series of articulated vertebrae, which encase the spinal cord. In this case the rachis usually form the supporting axis of the body and is then called the spine or vertebral column...
or midrib, and by the sori, which are slightly sunken into the lamina.
When Lellingeria was first described in 1991, it was thought to always have a radially symmetrical rhizome, but it has since been learned that some of the species that belong in Lellingeria have a dorsiventral rhizome. The unequally forked hairs are almost always present, but they are not a synapomorphy
Synapomorphy
In cladistics, a synapomorphy or synapomorphic character is a trait that is shared by two or more taxa and their most recent common ancestor, whose ancestor in turn does not possess the trait. A synapomorphy is thus an apomorphy visible in multiple taxa, where the trait in question originates in...
for Lellingeria.