- Kingdom: Animalia
- Phylum: Cnidaria
- Class: Anthozoa
- Subclass: Hexacorallia
- Order: Actiniaria
- Suborder: Nyantheae
- Family: Sagartiidae
- Scientific name: Sagartiogeton viduatus
- Norwegian: ålegressjørose
This is a small anemone, the stem rarely exceeds a length of 5 cm and a diameter of 1,5 cm. It has approximately 190 long, pale, translucent tentacles. There are often fine, green lines running along the stem, but these may be almost invisible or absent. It may be confused the partially buried S. undatus.
It lives on the stem of algae or even more frequently on the common eelgrass, Zostera marina. It is usually found in the subtidal zone, down to approximately 10 meters.
The distribution is uncertain, but it is known from the British Isles, Germany, the Netherlands and southern Scandinavia, at least north to Trøndelag, Norway.