- Kingdom: Animalia
- Phylum: Cnidaria
- Class: Hydrozoa
- Subclass: Hydroidolina
- Order: Leptothecata
- Family: Sertulariidae
- Scientific name: Thuiaria thuja
- Norwegian: -
Hydroid stage: The colony may grow to a height of 25 cm. Mature colonies takes a narrow and cylindrical bottle-brush shape, where the lower parts of the stem is without branches. Young colonies have a zigzag stem and alternating branches. On the similar T. articulata the stem is straight and the branches are usually opposite, rather than alternating. Other similar species have so far only been registered in arctic regions.
Medusa stage: No information.
It seems to thrive on hard substrate at any depth from the subtidal zone and down to 800 meters.
This species is regarded as circumpolar, and can be found from the Arctic to the temperate zone. In Europe it is found from Portugal to Scandinavia.