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River Jelly Lichen

This page provides information about the River Jelly Lichen, a fascinating organism with a unique jelly-like consistency when wet.

Scientific Name and Common Names

• Scientific Name: Collema dichotomum (With.) Coppins &amp J.R. Laundon
• Common Name: River Jelly Lichen

Taxonomy and Nomenclature

• Kingdom: Fungi (Lichens are a symbiotic relationship between fungi and algae or cyanobacteria)
• Family: Collemataceae
• Order: Lecanorales
• Synonyms: The text mentions Collema ohioense as a synonym for COLLEMA CONGLOMERATUM, and also includes lichen sclerosus et atrophicus, balanitis xerotica obliterans, lichen in the text.

Distribution and Habitat

• This lichen is aquatic and grows on submerged rocks and boulders in fast-flowing rivers.
• It has been found in the upper reaches of rivers in Northumberland.
• The populations of the river jelly lichen are thought to be the largest in Great Britain.

Morphological Characteristics

• The thallus (lichen body) forms flattened or erect, bright to dark green rosettes.
• It has convex, finger-like lobes that are one to two centimeters long.
• When wet, it becomes gelatinous.
• The thallus is foliose and can grow to 2-4 cm broad.

Ecological Role

• The text suggests the need to safeguard existing populations of river jelly lichen by guarding against developments such as outdoor river pursuits that might compromise conservation.

Interactions with Other Organisms

• The photobiont (photosynthetic partner) of this lichen is the cyanobacterium genus Nostoc.

Quirky Facts

• Collema dichotomum "looks more like a seaweed than a lichen."
• Some jelly lichens "absorb water until it is jelly-like".

Further Information

• ARKive (mentioned for River jelly lichen photos and facts)
• Encyclopedia of Life (mentioned for information about Collema dichotomum)
• APHOTOFUNGI - Photographic Stock Library
• APHOTOMARINE - Photographic Stock Library