Willea | |
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Willea rectangularis | |
Scientific classification ![]() | |
Clade: | Viridiplantae |
Division: | Chlorophyta |
Class: | Trebouxiophyceae |
Order: | Chlorellales |
Family: | Oocystaceae |
Genus: | Willea Schmidle [1] |
Species | |
Westella is a genus of green algae in the family Oocystaceae. It is found in freshwater habitats such as ponds and lakes, as part of the phytoplankton. [1] It has a cosmopolitan distribution. [2]
Willea consists of four-celled (rarely two-celled) colonies (termed coenobia); the coenobia may be aggregated to form compound colonies of 100 cells or more, arranged in a single plane. The cells are oval to cylindrical, arranged in a rectangle forming a rhomboidal gap. The cell walls are smooth. Cells are uninucleate, and contain a single parietal chloroplast; the chloroplast has a pyrenoid but this may be difficult to observe. [1] Asexual reproduction occurs by the formation of autospores, which are organized into coenobia; they enlarge with the cell wall, which eventually dissolves, releasing the new cells. Sexual reproduction and flagellated stages are not known in this genus. [1]
A number of species formerly included in the genus Crucigeniella are now placed in Willea; the name Crucigeniella is illegitimate. [2]