''Caldesia'' is a genus of aquatic plants. It includes three living species widespread across Europe, Asia, Africa and

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. The genus "has an extensive

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

through Pleistocene fossil record in Eurasia," and has been found in fossil strata of the United States ( Idaho and Vermont) as well. Ten fossil species have been described for the genus.

Taxonomy

The genus name of ''Caldesia'' is in honour of Ludovico (Luigi) Caldesi (1821 - 1884), an Italian politician and botanist. The genus was

circumscribed In geometry, the circumscribed circle or circumcircle of a polygon is a circle that passes through all the vertices of the polygon. The center of this circle is called the circumcenter and its radius is called the circumradius. Not every po ...

by Filippo Parlatore in Fl. Ital. Vol.3 on page 598 in 1860.

Description

Leaves all basal, floating or aerial, ovate to elliptical, cordate or subcordate. Flowers hermaphrodite, in racemes or panicles. Stamens 6(-11). Carpels few or numerous in a single whorl, free, each with 1 ovule; styles subventral. Fruitlets drupaceous, with woody endocarp and spongy exocarp, swollen, with a short subventral beak, smooth or with tubercles or spines.

Selected species

* '' Caldesia brandoniana'' † * '' Caldesia grandis'' Sam. - Assam, Bangladesh, southern

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

* '' Caldesia oligococca'' (F.Muell.) Buchanan **''Caldesia oligococca ''var''. acanthocarpa'' (F.Muell.) Hartog - Queensland, Northern Territory (of

) **''Caldesia oligococca ''var''. echinata'' Hartog - western Africa from Mali to

Chad Chad (; ar, تشاد , ; french: Tchad, ), officially the Republic of Chad, '; ) is a landlocked country at the crossroads of North and Central Africa. It is bordered by Libya to the north, Sudan to the east, the Central African Republic ...

, plus India, Pakistan,

Sri Lanka Sri Lanka (, ; si, ශ්‍රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...

, Thailand, Vietnam, Java **''Caldesia oligococca ''var''. oligococca'' - Timor, Queensland * ''

Caldesia parnassifolia ''Caldesia parnassifolia'', is an aquatic species in the Alismataceae. It is found in slow-moving fresh water. Distribution and habitat ''Caldesia parnassifolia'' occurs in lakes and ponds. It is known from Asian fresh waters of across much of Eu ...

'' (L.) Parl. (synonym: ''Caldesia reniformis'' (D.Don) Makino) - widespread across Europe, Asia, Africa, Queensland

References

Alismataceae Alismataceae genera Freshwater plants {{alismatales-stub