''Eichhornia'', commonly called water hyacinths, was a

polyphyletic A polyphyletic group is an assemblage that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies ...

genus of the aquatic

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

s family

Pontederiaceae Pontederiaceae is a Family (biology), family of flowering plants. The APG IV system of 2016 (unchanged from the APG III system of 2009, the APG II system of 2003 and the APG system of 1998) places the family in the order Commelinales, in the co ...

. Since it was consistently recovered in three independent lineages, it has been sunk into ''

Pontederia ''Pontederia'' 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. The genu ...

'', together with '' Monochoria''. Each of the three lineages is currently recognized as subgenera in ''Pontederia'': * ''Pontederia'' subg. ''Cabanisia'', which includes '' P. meyeri'', '' P. paniculata'' (the Brazilian water hyacinth), and '' P. paradoxa'' * ''Pontederia'' subg. ''Oshunae'', which includes the common water hyacinth, '' P. crassipes'' * ''Pontederia'' subg. ''Eichhornia'', which includes '' P. azurea'', '' P. diversifolia'', '' P. heterosperma'', and '' P. natans'' ''Pontederia'' subg. ''Eichhornia'' is pantropical, centered in

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

but with '' P. natans'' being endemic to continental

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

and

Madagascar Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...

. The other three species are restricted to the

Neotropics The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In biogeog ...

. It was named in honour of , an early-19th-century

Prussia Prussia (; ; Old Prussian: ''Prūsija'') was a Germans, German state centred on the North European Plain that originated from the 1525 secularization of the Prussia (region), Prussian part of the State of the Teutonic Order. For centuries, ...

n minister of education.

Description

Its species are

perennial In horticulture, the term perennial ('' per-'' + '' -ennial'', "through the year") is used to differentiate a plant from shorter-lived annuals and biennials. It has thus been defined as a plant that lives more than 2 years. The term is also ...

aquatic plant Aquatic plants, also referred to as hydrophytes, are vascular plants and Non-vascular plant, non-vascular plants that have adapted to live in aquatic ecosystem, aquatic environments (marine ecosystem, saltwater or freshwater ecosystem, freshwater ...

s (or hydrophytes) with prostrate and densely branched stems. The inflorescences can have one to 30 conspicuously attractive

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

s, mostly lavender to pink in colour, rarely white.

References

External links

* {{Authority control Freshwater plants Pontederiaceae Commelinales genera Historically recognized angiosperm genera