Ulvales
| Ulvales | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Sea lettuce ( ulva lactuca ) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Ulvales | ||||||||||||
| Blackman & Tansley |
The ulvales are an order of green algae . They are predominantly single-celled or thread-like (trichal) organized multicellular cells . There are also more highly organized species such as the sea lettuce and other members of the genus Ulva , which form a leaf-like two-layer thallus . Each cell contains only one chloroplast . Reproduction takes place vegetatively through flagellated zoospores or sexually , whereby the gametes of both sexes are also flagellated (anisogamy). The zoospores have two or four flagella, the gametes two. In addition to the purely haplontic life cycle, in which all cells except the zygote are haploid , there is also (as with Ulva ) a diplohaplontic cycle in which haploid and diploid generations alternate .
The order includes about 300 species. The most important families are the Ulvaceae with about 180 and the Ulvellaceae with about 110 species.
Individual evidence
- ^ Joachim W. Kadereit, Christian Körner, Benedikt Kost, Uwe Sonnewald: Strasburger Textbook of Plant Sciences . Springer Spectrum, Berlin / Heidelberg 2014, p. 596.
- ↑ AlgaeBase Taxonomy Detail: Order Ulvales , accessed June 29, 2018.
- ↑ Algaebase Taxonomy Browser: Order: Ulvales , accessed on May 10, 2018.