Callitriche
A genus of aquatic plants known as water-starwort.
Water-starworts, the genus *Callitriche*, are mostly aquatic plants. Although *Callitriche* was once the sole genus in the family Callitrichaceae, the APG II system now places it within the plantain family, Plantaginaceae. The older family name, Callitrichaceae, is still preserved as a *nomen conservandum*.
The genus contains 75 accepted species. A molecular phylogeny of 50 species identified three main clades: Clade A (three widespread species), Clade C (ten New World species), and Clade D (six European species). Parsimony analysis indicates that aneuploid reduction (from n=5 to n=4) and polyploidy (from n=5 to n=10) each evolved at least twice within the genus. The fully submerged growth form and hypohydrophily (underwater pollination) each evolved only once.
Quick Facts
- Taxon
- Callitriche
Facts from the source article.
Lore & Background
Callitriche is a genus of largely aquatic plants known as water-starwort. Previously, it was the only genus in the family Callitrichaceae, but according to the APG II system this family is now included in the Plantaginaceae (plantain family). The family name Callitrichaceae retains its status as nomen conservandum (name to be retained).
The first molecular phylogeny of the aquatic genus of 50 species discerned three clades: Clade A (three species, widespread); Clade C (10 species, New World); Clade D (six species, Europe). The parsimony analyses revealed that aneuploid reduction (n=5 to 4) and polyploidy (n=5 to 10) have evolved at least twice in the genus, whereas the obligately submersed growth habit and hypohydrophily have evolved once.
Seventy-five species are accepted, including Callitriche antarctica (Antarctic water-starwort), Callitriche brutia (pedunculate water starwort), Callitriche hermaphroditica (autumn water starwort), and Callitriche stagnalis (pond water starwort).
Reader's Guide
The genus Callitriche is significant as a group of aquatic plants that were once placed in their own family, Callitrichaceae, but are now included in Plantaginaceae under the APG II system, with the family name retained as nomen conservandum. The first molecular phylogeny of 50 species identified three clades, revealing evolutionary patterns such as aneuploid reduction and polyploidy occurring at least twice, and the single evolution of obligately submersed growth and hypohydrophily. With 75 accepted species, the genus has a global distribution, including species like Callitriche antarctica from Antarctica and Callitriche hermaphroditica from temperate regions. The taxonomy includes numerous synonyms, reflecting historical classification efforts. The genus serves as a model for studying aquatic plant evolution and adaptation, particularly in relation to pollination and chromosome number changes. Its legacy is rooted in its systematic reclassification and the insights it provides into plant phylogeny and reproductive biology.
Did You Know?
- Callitriche was previously the only genus in the family Callitrichaceae.
- The first molecular phylogeny of the genus discerned three clades: Clade A, Clade C, and Clade D.
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