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River Jelly Lichen: An Overview

This page provides an overview of various lichens, primarily focusing on those referred to as "jelly lichens," and in particular the "Conglomerate Jelly Lichen."

Scientific Name and Common Names

• Scientific Name: Collema conglomeratum Hoffm.
• Common Names: Conglomerate Jelly Lichen, River Jelly Lichen, Jelly Lichen

Taxonomy and Nomenclature

• Kingdom: Not explicitly stated, but implied to be Fungi due to the presence of lichens
• Group: Lichen
• Family: Collemataceae
• Genus: Collema
• Synonyms:
  • Collema cyrtaspis Tuck.
  • Collema pycnocarpum Nyl.
  • Gabura conglomerata
• Other Varieties: Collema conglomeratum var. crassiusculum (Malme) Degel.

Distribution and Habitat

• Prefers silica-rich submerged rocks, such as sandstone and volcanic rocks, but rarely found on limestone.
• Found on various rock types including sandstones, conglomerates, basalts, and even mortar.

Ecological Role

• Lichens can produce weak acids that dissolve the substrate of calcareous (limestone) rocks.

Morphological Characteristics and Growth Habits

• Small (1-2 cm), finger-like lobed.
• Described as gelatinous or jelly-like when wet, and can appear dark blue-green, blue-gray, or almost black.
• The photobiont (the photosynthetic partner in the lichen symbiosis) is the cyanobacterium genus Nostoc.

Interactions with Other Organisms

• Lichens, including jelly lichens, can grow on rocks after initial colonization by bacteria.
• Often found in conjunction with other lichens and occasionally fungi on conglomerate boulders.

Further Information

• Dave's Garden
• LIAS (Recent Literature on Lichens)

Quirky Facts

• The texture of the rock, where River Jelly Lichen can be found, can be basic to neutral and often rough, including sandstones and conglomerates.