Pontederiaceae
Encyclopedia
Pontederiaceae is the botanical name
of a family
of flowering plant
s.
The APG II system
, of 2003 (unchanged from the APG system
, of 1998) places the family in the order Commelinales
, in the commelinid clade
, in the monocots
. It is a small family of heterostylous
aquatic plant
s, occurring in tropical
and subtropical
waters. Charles Darwin
was interested in the specialized form of heterostyly
found in the family, known as tristyly. Not all of the species are heterostylous. The family probably contains fewer than three dozen species.
It is best known for the water hyacinth (Eichhornia crassipes
), which is an invasive species
in many waterways. The highly modified Hydrothrix gardneri
is a submerged aquatic with a two-flowered pseudanthium
.
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...
of a 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...
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.
The APG II system
APG II system
The APG II system of plant classification is the second, now obsolete, version of a modern, mostly molecular-based, system of plant taxonomy that was published in April 2003 by the Angiosperm Phylogeny Group. It was a revision of the first APG system, published in 1998, and was superseded in 2009...
, of 2003 (unchanged from the APG system
APG system
The APG system of plant classification is the first, now obsolete, version of a modern, mostly molecular-based, system of plant taxonomy that was published in 1998 by the Angiosperm Phylogeny Group. It was superseded in 2003 by a revision, the APG II system, and then in 2009 by a further...
, of 1998) places the family in the order Commelinales
Commelinales
Commelinales is the botanical name of an order of flowering plants. It comprises five families: Commelinaceae, Haemodoraceae, Hanguanaceae, Philydraceae, and Pontederiaceae. All the families combined contain over 800 species in about 70 genera; the majority of species are in the Commelinaceae...
, in the commelinid 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 monocots
Monocotyledon
Monocotyledons, also known as monocots, are one of two major groups of flowering plants that are traditionally recognized, the other being dicotyledons, or dicots. Monocot seedlings typically have one cotyledon , in contrast to the two cotyledons typical of dicots...
. It is a small family of heterostylous
Heterostyly
Heterostyly is a unique form of polymorphism and herkogamy in flowers. In a heterostylous species, two or three different morphological types of flowers, termed morphs, exist in the population. On each individual plant, all flowers share the same morph. The flower morphs differ in the lengths of...
aquatic plant
Aquatic plant
Aquatic plants are plants that have adapted to living in aquatic environments. They are also referred to as hydrophytes or aquatic macrophytes. These plants require special adaptations for living submerged in water, or at the water's surface. Aquatic plants can only grow in water or in soil that is...
s, occurring in tropical
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...
and subtropical
Subtropics
The subtropics are the geographical and climatical zone of the Earth immediately north and south of the tropical zone, which is bounded by the Tropic of Cancer and the Tropic of Capricorn, at latitudes 23.5°N and 23.5°S...
waters. Charles Darwin
Charles Darwin
Charles Robert Darwin FRS was an English naturalist. He established that all species of life have descended over time from common ancestry, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.He published his theory...
was interested in the specialized form of heterostyly
Heterostyly
Heterostyly is a unique form of polymorphism and herkogamy in flowers. In a heterostylous species, two or three different morphological types of flowers, termed morphs, exist in the population. On each individual plant, all flowers share the same morph. The flower morphs differ in the lengths of...
found in the family, known as tristyly. Not all of the species are heterostylous. The family probably contains fewer than three dozen species.
It is best known for the water hyacinth (Eichhornia crassipes
Eichhornia crassipes
Eichhornia crassipes, commonly known as Common Water Hyacinth, is an aquatic plant native to the Amazon basin, and is often considered a highly problematic invasive species outside its native range.-Ecology:...
), which is an invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
in many waterways. The highly modified Hydrothrix gardneri
Hydrothrix gardneri
Hydrothrix is a monotypic flowering plant genus in the family Pontederiaceae.The highly modified Hydrothrix gardneri is a submerged aquatic with a two-flowered pseudanthium found in Eastern Brazil. It is used as an aquarium plant....
is a submerged aquatic with a two-flowered pseudanthium
Pseudanthium
A pseudanthium or flower head is a special type of inflorescence, in which several flowers are grouped together to form a flower-like structure. The real flowers are generally small and greatly reduced, but can sometimes be quite large...
.
Taxonomy
There are 9 genera within this family as below.- EichhorniaWater hyacinthThe seven species of water hyacinth comprise the genus Eichhornia. Water hyacinth are a free-floating perennial aquatic plant native to tropical and sub-tropical South America. With broad, thick, glossy, ovate leaves, water hyacinth may rise above the surface of the water as much as 1 meter in...
KunthCarl Sigismund KunthCarl Sigismund Kunth , also Karl Sigismund Kunth or anglicized as Charles Sigismund Kunth, was a German botanist... - Eurystemon
- HeterantheraHeterantheraHeteranthera is a genus of aquatic plants in the water hyacinth family, Pontederiaceae, known generally as mud plantains. Species of this genus are native to tropical and subtropical America and Africa. They live in the water or in wet soils. They produce leaves on long petioles and some are...
Ruiz & Pav.Ruiz y Pavón-Ruiz et Pavón:Ruiz y Pavón Spanish form of the combination Ruiz et Pavón, as used as authority in plant species.-Joseph Pavón:Jose Antonio Pavón y Jimenez Spanish botanist, with Hipólito Ruiz López and the French specialist Dombey visited between 1779 and 1788 Chile, Peru and other South American... - Hydrothrix
- Monochoria C.Presl
- PontederiaPontederiaPontederia is a genus of tristylous aquatic plants, members of which are commonly known as pickerel weeds. Pontederia is endemic to the Americas, distributed from Canada to Argentina, where it is found in shallow water or on mud...
L. - Reussia
- Scholleropsis H.PerrierJoseph Marie Henry Alfred Perrier de la BâthieJoseph Marie Henry Alfred Perrier de la Bâthie was a French botanist who specialized in the plants of Madagascar. He delineated the two chief floristic provinces of Madagascar...
- Zosterella
External links
- Pontederiaceae in L. Watson and M.J. Dallwitz (1992 onwards).
- The families of flowering plants: descriptions, illustrations, identification, information retrieval. Version: 9 March 2006. http://delta-intkey.com.
- Pontederiaceae in the Flora of North America
- Pontederiaceae in the Flora of China
- NCBI Taxonomy Browser
- links at CSDL