Davalliaceae
Encyclopedia
Davalliaceae is a family
of fern
s in the order
Polypodiales
. It is sister to the largest family of ferns, Polypodiaceae
, and shares some morphological
characters with it.
Davalliaceae is native
to tropical and subtropical regions of the Pacific
, Australia
, Asia
, and Africa
. They are small to medium in size. In the wild
, they are usually epiphytic, sometimes epipetric
or terrestrial
.
Many species of Davallia are in cultivation
, with Davallia tyermanii, Davallia fejeensis
, and Davallia solida being perhaps the most well-known. A key
to the cultivated species of Davallia is available. Davallodes, Humata, and Wibelia have species in cultivation as well.
In Davalliaceae, many of the species are closely related
and hard to distinguish
from each other. In 1990, a treatment
of Davalliaceae estimated the number of species at 110. A 2008 paper listed all of the species, recognizing only 63. A new species, Davallia napoensis was described in 2011.
. Rhizome
s dictyostelic
, dorsiventral
, densely scaly
. Stipes
articulate at base. Phyllopodia short. veins free
. Sporangium
stalk 3-rowed. Annulus vertical. Spore
s monolete.
with Selliguea
and others in the family Polypodiaceae. Leucostegia is in the family Hypodematiaceae
, which consists of Hypodematium
and Leucostegia, and possibly Didymochlaena as well.
In 2008, a molecular phylogenetic study
of Davalliaceae showed that none of the polyspecific
genera recognized at that time were monophyletic. In that same year, a revision of the family divided it into five genera. One of these, Araiostegiella, was newly described. The genus Davallia was divided into two sections
, named
Davallia and Trogostolon.
The monotypic genera Trogostolon and Parasorus have not been sampled
for DNA
. Anatomical
studies indicate that Trogostolon, along with several species of Davallia, belongs in Davallia section Trogostolon. Likewise, Parasorus seems to belong to one of the two clades that constitute the genus Humata. The genus Pachypleuria included nearly all of the species that are now in Humata. It was found to be paraphyletic over the type species
of Humata, and is no longer recognized.
Davallodes, Paradavallodes, and Araiostegia are very closely related and their circumscriptions
have varied greatly from one author to another. In 2008, Davallodes was expanded to include all of Paradavallodes, and all but three species of Araiostegia. Because the type species of Araiostegia had been transferred to Davallodes, these three species were given a new generic name, Araiostegiella.
The genus Wibelia contains eight species, and was resurrected from Davallia, which it closely resembles.
is based on one that was published in 2008.
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...
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 order
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
Polypodiales
Polypodiales
The order Polypodiales encompasses the major lineages of polypod ferns, which comprise more than 80% of today's fern species. They are found in many parts of the world including tropical, semitropical and temperate areas...
. It is sister to the largest family of ferns, 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:...
, and shares some 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 with it.
Davalliaceae is 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 and subtropical regions of the Pacific
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....
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
, and 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...
. They are small to medium in size. In the wild
Wildlife
Wildlife includes all non-domesticated plants, animals and other organisms. Domesticating wild plant and animal species for human benefit has occurred many times all over the planet, and has a major impact on the environment, both positive and negative....
, they are usually epiphytic, sometimes epipetric
Epipetric
An epipetric plant, is one that is found growing on rocks. Many ferns fall into this category of plant habitat, including Asplenium . Epipetric plants are called Lithophytes....
or terrestrial
Terrestrial plant
A terrestrial plant is one that grows on land. Other types of plants are aquatic , epiphytic , lithophytes and aerial ....
.
Many species of Davallia are in cultivation
Gardening
Gardening is the practice of growing and cultivating plants. Ornamental plants are normally grown for their flowers, foliage, or overall appearance; useful plants are grown for consumption , for their dyes, or for medicinal or cosmetic use...
, with Davallia tyermanii, Davallia fejeensis
Davallia fejeensis
Davallia fejeensis is a species of fern in the Davalliaceae family.-References:*CV Morton, Observations on Cultivated Ferns, IV. The Species of Davallia, American Fern Journal....
, and Davallia solida being perhaps the most well-known. A key
Identification key
In biology, an identification key is a printed or computer-aided device that aids the identification of biological entities, such as plants, animals, fossils, microorganisms, and pollen grains...
to the cultivated species of Davallia is available. Davallodes, Humata, and Wibelia have species in cultivation as well.
In Davalliaceae, many of the species are closely related
Introduction to evolution
Evolution is the process of change in all forms of life over generations, and evolutionary biology is the study of how evolution occurs. The biodiversity of life evolves by means of mutations, genetic drift and natural selection....
and hard to distinguish
Identification (biology)
Identification in biology is the process of assigning a pre-existing individual or class name to an individual organism. Identification of organisms to individual names may be based on individualistic natural body features Identification in biology is the process of assigning a pre-existing...
from each other. In 1990, a treatment
Treatise
A treatise is a formal and systematic written discourse on some subject, generally longer and treating it in greater depth than an essay, and more concerned with investigating or exposing the principles of the subject.-Noteworthy treatises:...
of Davalliaceae estimated the number of species at 110. A 2008 paper listed all of the species, recognizing only 63. A new species, Davallia napoensis was described in 2011.
Genera
- Araiostegiella M.Kato & Tsutsumi
- DavalliaDavalliathumb|right|245px|[[Davallia solida var. pyxidata|"Hare's Foot"]] on [[Sydney sandstone|sandstone]], [[Ku-ring-gai Chase National Park]], [[Australia]]...
James Edward SmithJames Edward SmithSir James Edward Smith was an English botanist and founder of the Linnean Society.Smith was born in Norwich in 1759, the son of a wealthy wool merchant. He displayed a precocious interest in the natural world...
- Davallodes E.B. CopelandEdwin CopelandEdwin Bingham Copeland was an American botanist and agriculturist. In 1909, he founded the Philippines College of Agriculture at Los Baños, Laguna—what is now known as the University of the Philippines, Los Baños, and served as its dean and also as a professor of plant physiology for eight...
- Humata A.J. CavanillesAntonio José CavanillesAntonio José Cavanilles was a leading Spanish taxonomic botanist of the 18th century. He named many plants, particularly from Oceania, his name is abbreviated as Cav...
- Wibelia BernhardiJohann Jakob BernhardiJohann Jakob Bernhardi was a German doctor and botanist.This botanist is denoted by the author abbreviation Bernh. when citing a botanical name.-Biography:Johann J...
Description
Usually epiphytic or epipetricEpipetric
An epipetric plant, is one that is found growing on rocks. Many ferns fall into this category of plant habitat, including Asplenium . Epipetric plants are called Lithophytes....
. 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...
s dictyostelic
Stele (biology)
In a vascular plant, the stele is the central part of the root or stem containing the tissues derived from the procambium. These include vascular tissue, in some cases ground tissue and a pericycle, which, if present, defines the outermost boundary of the stele...
, dorsiventral
Dorsiventral
Dorsiventral is a term used to describe an organ which has two surfaces differing from each other in appearance and structure, as an ordinary leaf. In biology, this term also refers to that which extends from a dorsal to a ventral surface....
, densely scaly
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 :...
. Stipes
Stipe (botany)
In botany, a stipe is a stalk that supports some other structure. The precise meaning is different depending on which taxonomic group is being described....
articulate at base. Phyllopodia short. veins free
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....
. Sporangium
Sporangium
A sporangium is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. All plants, fungi, and many other lineages form sporangia at some point in their life cycle...
stalk 3-rowed. Annulus vertical. Spore
Spore
In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...
s monolete.
History
Gymnogrammitis and Leucostegia were once included in Davalliaceae, but these are now known to belong elsewhere. Gymnogrammitis is in a cladeClade
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...
with Selliguea
Selliguea
Selliguea is a fern genus in the family Polypodiaceae.-Species list:* Selliguea albicaula M.Kato & M.G.Price; Acta Phytotax. Geobot. 41: 72...
and others in the family Polypodiaceae. Leucostegia is in the family Hypodematiaceae
Hypodematiaceae
Hypodematiaceae is a family of ferns in the order Polypodiales. It consists of two, or possibly three, small genera. Hypodematium and Leucostegia are always included, and Didymochlaena might best be placed in this family as well....
, which consists of Hypodematium
Hypodematium
-Species:*Hypodematium crenatum Kuhn*Hypodematium daochengense K. H. Shing*Hypodematium fordii Ching*Hypodematium glabrius Holtt.*Hypodematium glabrum Ching ex Shing*Hypodematium glandulosum Ching ex Shing...
and Leucostegia, and possibly Didymochlaena as well.
In 2008, a molecular phylogenetic 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...
of Davalliaceae showed that none of the polyspecific
Monospecificity
In zoology, "monospecific" is an adjective describing a genus which contains only one known species. The term comes from the Greek prefix "μονο-" meaning "single" and Latin "species" meaning "kind" or "type". It is thus of hybrid origin....
genera recognized at that time were monophyletic. In that same year, a revision of the family divided it into five genera. One of these, Araiostegiella, was newly described. The genus Davallia was divided into two 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...
, 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...
Davallia and Trogostolon.
The monotypic genera Trogostolon and Parasorus have not been sampled
Sample (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...
for DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
. Anatomical
Plant anatomy
Plant anatomy or phytotomy is the general term for the study of the internal structure of plants. While originally it included plant morphology, which is the description of the physical form and external structure of plants, since the mid-20th century the investigations of plant anatomy are...
studies indicate that Trogostolon, along with several species of Davallia, belongs in Davallia section Trogostolon. Likewise, Parasorus seems to belong to one of the two clades that constitute the genus Humata. The genus Pachypleuria included nearly all of the species that are now in Humata. It was found to be paraphyletic over 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...
of Humata, and is no longer recognized.
Davallodes, Paradavallodes, and Araiostegia are very closely related and their circumscriptions
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....
have varied greatly from one author to another. In 2008, Davallodes was expanded to include all of Paradavallodes, and all but three species of Araiostegia. Because the type species of Araiostegia had been transferred to Davallodes, these three species were given a new generic name, Araiostegiella.
The genus Wibelia contains eight species, and was resurrected from Davallia, which it closely resembles.
Phylogeny
The following phylogenetic treePhylogenetic 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...
is based on one that was published in 2008.