Trapa

Trapa is a genus of floating annual aquatic plants in the Lythraceae family. A well-known species in the genus is Trapa natans, grown as a food crop in China and the Indian subcontinent.

Evolution

Fossil record

file:Trapa americana SRUI SRDU img01.jpg|thumb|upright|Trapa americana, Latah Formation, North America
The genus Trapa has an extensive fossil record, with numerous, distinctive species. Undisputed fossilized seeds have been found in Cenozoic strata starting from the Eocene throughout Europe, China and North America. The oldest known fossils attributed to the genus are of leaves from Cretaceous Alaska, referred to the species, T. borealis.

Taxonomy

The genus Trapa and its type species T. natans were named by the Swedish botanist Carl Linnaeus in his Species Plantarum in 1753. The generic name Trapa is derived from a late Latin word for a caltrop, calcitrappa, an area denial weapon. The specific name natans is the Latin for swimming or floating, from the verb nato, "I swim". As of 2023, there are eight recognised species, T. assamica, T. hankensis, T. hyrcana, T. incisa, T. kashmirensis, T. kozhevnikoviorum , T. natans, and T. nedoluzhkoi.