Cryptostomata (singular: cryptostoma) are structures found in some types of

brown algae Brown algae (singular: alga), comprising the class Phaeophyceae, are a large group of multicellular algae, including many seaweeds located in colder waters within the Northern Hemisphere. Brown algae are the major seaweeds of the temperate an ...

. The anatomical structures are found in some species of '' Fucus'', but not in ''

Pelvetia canaliculata ''Pelvetia canaliculata'', the channelled wrack, is a very common brown alga (Phaeophyceae) found on the rocks of the upper shores of Europe. It is the only species remaining in the monotypic genus ''Pelvetia''. In 1999, the other members of th ...

''. They are conceptacles, sterile cavities, producing only hairs. They are found on the lamina of ''Fucus serratus''. Colourless tufts of hairs can be seen issuing from them. They are also sometimes referred to by the German name of Fasergrübchen.

References

{{reflist Algal anatomy