Icacinaceae
Encyclopedia
Icacinaceae is a family
of flowering plant
s.
It consists of tree
s, shrub
s, and liana
s, primarily of the tropics
.
The family was traditionally circumscribed
quite broadly, with around 55 genera
totalling over 400 species
. However in 2001 this circumscription was found to be polyphyletic, and the family was split into four families in three different orders
: Icacinaceae sensu stricto (unplaced at order rank), Pennantiaceae (Apiales
), Stemonuraceae (Aquifoliales
) and Cardiopteridaceae
(also Aquifoliales). Icacinaceae sensu stricto contains about 150 species, distributed into about 35 genera. One genus was named in 2005. Icacinaceae sensu stricto is not monophyletic, but further studies
will be needed before anyone can determine how it should be divided into segregate
families.
Icacina senegalensis extracts have shown activity against malaria parasites.
described Apodytes and Pogopetalum as new genera
and united them with Icacina, Gomphandra, and Leretia to create the tribe
Icacineae of what would later be called the family Olacaceae
. Olacaceae was at that time, and through the 20th century, defined broadly, encompassing several families in the order
Santalales
. Pogopetalum was later synonymized
with Emmotum.
In 1852, John Miers
argued
that Bentham's Icacineae did not belong in Olacaceae and he raised them to the taxonomic rank
of family as Icacinaceae.
Philippe van Tieghem realized that the family Icacinaceae, as circumscribed
by Miers, consisted of groups that were only distantly related, and in 1897, he divided it into seven families. Van Tieghem's treatment in some ways anticipated the results of 21st century phylogenetic studies
, in particular, by his establishment of the families Emmotaceae and Leptaulaceae. His division of Icacinaceae into smaller families was not accepted and other authors continued to define Icacinaceae in the broad sense, known as Icacinaceae sensu lato.
In 1942, Hermann Sleumer
defined Icacinaceae broadly in his coverage of the family for Die Natürlichen Pflanzenfamilien. Later authors did likewise.
In the 1940s, Richard A. Howard wrote a series of papers on several of the genera. Sleumer wrote about the Asia
n genera in 1969, and the Malesia
n genera in 1971. Much of what is known about the family comes from regional floras such as Flora of Australia
and Flora of China.
In 2001, Jesper Kårehed, using a combination of morphological
and DNA sequence
data, showed that Icacinaceae sensu lato was distantly polyphyletic and was, at least arguably, the worst of the plant families. It is now known to have rivaled Flacourtiaceae
as an unnatural assemblage of disparate groups. Kårehed divided it into four families: Pennantiaceae, Stemonuraceae, Cardiopteridaceae
, and Icacinaceae sensu stricto.
Pennantiaceae consists of the single genus Pennantia
and is the most basal
clade
in the campanulid order Apiales
.
Stemonuraceae is a family of 12 genera in the campanulid order Aquifoliales. It is sister to Cardiopteridaceae.
Before the phylogeny produced by Kårehed, Cardiopteridaceae contained only Cardiopteris. Kårehed transferred Citronella
, Gonocaryum, and Leptaulus from Icacinaceae to this family, and provisionally placed Metteniusa
, Dendrobangia, and Pseudobotrys there as well. Metteniusa was shown to be a lamiid in 2007, and was placed in a family by itself. The affinities of Dendrobangia and Pseudobotrys remain obscure.
Some authors have continued to maintain Cardiopteridaceae as a monogeneric family, placing Citronella, Gonocaryum, Leptaulus, Dendrobangia, and Pseudobotrys in Leptaulaceae. The study by Kårehed showed Cardiopteris to be embedded in Leptaulaceae, but statistical support
for this position was not strong.
Icacinaceae sensu stricto consists of about 35 genera of lamiids and is not a monophyletic group. Icacina and some close relatives are probably related to the order Garryales
and might well be placed within it. Cassinopsis, Emmotum, Apodytes, and a few others probalby belong elsewhere among the lamiids. Apodytes and Rhaphiostylis might be closer to Oncothecaceae than to anything else. The division of the lamiids into orders is still uncertain. More phylogenetic studies will be needed to resolve these issues.
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 flowering plant
Flowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
s.
It consists of tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
s, shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
s, and liana
Liana
A liana is any of various long-stemmed, woody vines that are rooted in the soil at ground level and use trees, as well as other means of vertical support, to climb up to the canopy to get access to well-lit areas of the forest. Lianas are especially characteristic of tropical moist deciduous...
s, primarily of the tropics
Tropics
The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately N and the Tropic of Capricorn in the southern hemisphere at S; these latitudes correspond to the axial tilt of the Earth...
.
The family was traditionally 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....
quite broadly, with around 55 genera
Genera
Genera is a commercial operating system and development environment for Lisp machines developed by Symbolics. It is essentially a fork of an earlier operating system originating on the MIT AI Lab's Lisp machines which Symbolics had used in common with LMI and Texas Instruments...
totalling over 400 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...
. However in 2001 this circumscription was found to be polyphyletic, and the family was split into four families in three different orders
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...
: Icacinaceae sensu stricto (unplaced at order rank), Pennantiaceae (Apiales
Apiales
The Apiales are an order of flowering plants. The families given at right are those recognized in the APG III system. This is typical of the newer classifications, though there is some slight variation, and in particular the Torriceliaceae may be divided...
), Stemonuraceae (Aquifoliales
Aquifoliales
The Aquifoliales are an order of flowering plants, including most notably the Aquifoliaceae, or holly family, and also the Helwingiaceae and the Phyllonomaceae . In 2001, the families Stemonuraceae and Cardiopteridaceae were added to this order...
) and Cardiopteridaceae
Cardiopteridaceae
Cardiopteridaceae is a eudicot family of flowering plants. It consists of about 43 species of trees, shrubs, and woody vines, mostly of the tropics, but with a few in temperate regions. It contains six genera, the largest of which is Citronella, with 21 species. The other genera are much smaller...
(also Aquifoliales). Icacinaceae sensu stricto contains about 150 species, distributed into about 35 genera. One genus was named in 2005. Icacinaceae sensu stricto is not monophyletic, but further studies
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...
will be needed before anyone can determine how it should be divided into segregate
Segregate (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...
families.
Icacina senegalensis extracts have shown activity against malaria parasites.
Genera
The following list of genera was created from several sources. The last column contains those genera whose inclusion in the family is especially doubtful.
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History
In 1841, George BenthamGeorge Bentham
George Bentham CMG FRS was an English botanist, characterized by Duane Isely as "the premier systematic botanist of the nineteenth century".- Formative years :...
described Apodytes and Pogopetalum as new genera
Genera
Genera is a commercial operating system and development environment for Lisp machines developed by Symbolics. It is essentially a fork of an earlier operating system originating on the MIT AI Lab's Lisp machines which Symbolics had used in common with LMI and Texas Instruments...
and united them with Icacina, Gomphandra, and Leretia to create the 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...
Icacineae of what would later be called the family Olacaceae
Olacaceae
Olacaceae is a family of flowering plants in the order Santalales. They are woody plants, native throughout the tropical regions of the world....
. Olacaceae was at that time, and through the 20th century, defined broadly, encompassing several families 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...
Santalales
Santalales
Santalales is an order of flowering plants with a cosmopolitan distribution, but heavily concentrated in tropical and subtropical regions.Most have seeds without a testa, which is unusual for flowering plants...
. Pogopetalum was later synonymized
Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...
with Emmotum.
In 1852, John Miers
John Miers (botanist)
John Miers, FRS FLS, knight grand cross of the Order of the Rose, was a British botanist and engineer, best known for his work on the flora of Chile and Argentina....
argued
Argument
In philosophy and logic, an argument is an attempt to persuade someone of something, or give evidence or reasons for accepting a particular conclusion.Argument may also refer to:-Mathematics and computer science:...
that Bentham's Icacineae did not belong in Olacaceae and he raised them to the taxonomic rank
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...
of family as Icacinaceae.
Philippe van Tieghem realized that the family Icacinaceae, as 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....
by Miers, consisted of groups that were only distantly related, and in 1897, he divided it into seven families. Van Tieghem's treatment in some ways anticipated the results of 21st century phylogenetic studies
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...
, in particular, by his establishment of the families Emmotaceae and Leptaulaceae. His division of Icacinaceae into smaller families was not accepted and other authors continued to define Icacinaceae in the broad sense, known as Icacinaceae sensu lato.
In 1942, Hermann Sleumer
Hermann Otto Sleumer
Hermann Otto Sleumer was a Dutch botanist of German birth. The plant genera Sleumerodendron Virot and Sleumeria Utteridge, Nagam. & Teo , are named for him....
defined Icacinaceae broadly in his coverage of the family for Die Natürlichen Pflanzenfamilien. Later authors did likewise.
In the 1940s, Richard A. Howard wrote a series of papers on several of the genera. Sleumer wrote about the 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...
n genera in 1969, and the Malesia
Malesia
Malesia is a biogeographical region straddling the boundaries of the Indomalaya ecozone and Australasia ecozone, and also a phytogeographical floristic region in the Paleotropical Kingdom.-Floristic province:...
n genera in 1971. Much of what is known about the family comes from regional floras such as Flora of Australia
Flora of Australia (series)
The Flora of Australia is a 59 volume series describing the vascular plants, bryophytes and lichens present in Australia and its external territories...
and Flora of China.
In 2001, Jesper Kårehed, using a combination of 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...
and 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...
data, showed that Icacinaceae sensu lato was distantly polyphyletic and was, at least arguably, the worst of the plant families. It is now known to have rivaled Flacourtiaceae
Flacourtiaceae
Flacourtiaceae is a defunct family of flowering plants whose former members have been scattered to various other families, mostly to Achariaceae, Samydaceae, and Salicaceae. It was so vaguely defined that hardly anything seemed out of place there and it became a dumping ground for odd and anomalous...
as an unnatural assemblage of disparate groups. Kårehed divided it into four families: Pennantiaceae, Stemonuraceae, Cardiopteridaceae
Cardiopteridaceae
Cardiopteridaceae is a eudicot family of flowering plants. It consists of about 43 species of trees, shrubs, and woody vines, mostly of the tropics, but with a few in temperate regions. It contains six genera, the largest of which is Citronella, with 21 species. The other genera are much smaller...
, and Icacinaceae sensu stricto.
Pennantiaceae consists of the single genus Pennantia
Pennantia
Pennantia is the sole genus in the plant family Pennantiaceae. In older classifications, it was placed in the family Icacinaceae. Most authorities have recognized three or four species, depending on whether they recognized Pennantia baylisiana as a separate species from Pennantia endlicheri. ...
and is the most basal
Basal (phylogenetics)
In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...
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...
in the campanulid order Apiales
Apiales
The Apiales are an order of flowering plants. The families given at right are those recognized in the APG III system. This is typical of the newer classifications, though there is some slight variation, and in particular the Torriceliaceae may be divided...
.
Stemonuraceae is a family of 12 genera in the campanulid order Aquifoliales. It is sister to Cardiopteridaceae.
Before the phylogeny produced by Kårehed, Cardiopteridaceae contained only Cardiopteris. Kårehed transferred Citronella
Citronella
Citronella is a word used for several things, including:* Citronella , a genus of trees and shrubs in the Cardiopteridaceae* Citronella oil, an insect-repelling essential oil derived from Cymbopogon...
, Gonocaryum, and Leptaulus from Icacinaceae to this family, and provisionally placed Metteniusa
Metteniusa
Metteniusa is a genus of flowering plants in the monogeneric family Metteniusaceae. It was named by Hermann Karsten in 1860 for the German botanist Georg Heinrich Mettenius. It has seven species. The type species is Metteniusa edulis...
, Dendrobangia, and Pseudobotrys there as well. Metteniusa was shown to be a lamiid in 2007, and was placed in a family by itself. The affinities of Dendrobangia and Pseudobotrys remain obscure.
Some authors have continued to maintain Cardiopteridaceae as a monogeneric family, placing Citronella, Gonocaryum, Leptaulus, Dendrobangia, and Pseudobotrys in Leptaulaceae. The study by Kårehed showed Cardiopteris to be embedded in Leptaulaceae, but statistical support
Resampling (statistics)
In statistics, resampling is any of a variety of methods for doing one of the following:# Estimating the precision of sample statistics by using subsets of available data or drawing randomly with replacement from a set of data points # Exchanging labels on data points when performing significance...
for this position was not strong.
Icacinaceae sensu stricto consists of about 35 genera of lamiids and is not a monophyletic group. Icacina and some close relatives are probably related to the order Garryales
Garryales
The Garryales are a small order of dicotyledons, including only two families and three genera:* Family Garryaceae**Garrya**Aucuba* Family Eucommiaceae**Eucommia...
and might well be placed within it. Cassinopsis, Emmotum, Apodytes, and a few others probalby belong elsewhere among the lamiids. Apodytes and Rhaphiostylis might be closer to Oncothecaceae than to anything else. The division of the lamiids into orders is still uncertain. More phylogenetic studies will be needed to resolve these issues.