Definition
Collematineae is a suborder of lichen‑forming fungi within the order Peltigerales, class Lecanoromycetes (phylum Ascomycota).
Overview
The suborder groups several families of predominantly foliose and gelatinous lichens that associate chiefly with cyanobacterial photobionts. Members are widely distributed, occurring in temperate to tropical habitats, often on soil, mosses, or bark. The taxon was established to reflect molecular phylogenetic relationships that distinguish these lineages from other clades within Peltigerales.
Etymology / Origin
The name derives from the type genus Collema, combined with the suffix “‑ineae,” which is used in botanical nomenclature to denote a suborder. Collema itself stems from the Greek “κολλή” (kollē), meaning “glue,” referring to the gelatinous texture of the thallus.
Characteristics
- Lichenisation: All members are obligately lichenised, forming symbiotic associations primarily with cyanobacteria of the genus Nostoc or related taxa.
- Thallus morphology: Thalli are typically gelatinous, foliose, or squamulose, becoming swollen when wet due to the presence of cyanobacterial cells and polysaccharide matrices.
- Reproductive structures: Ascomata are usually apothecia; spores are ellipsoid to fusiform, often bearing a thin wall and lacking pronounced ornamentation.
- Chemistry: Secondary metabolites are relatively simple; many species lack the diverse lichen substances found in other lichens, though some produce depsides or depsidones.
- Ecology: Species often inhabit nutrient‑rich, moist environments such as forest floors, stream banks, and alpine bogs. Their cyanobacterial partners enable nitrogen fixation, contributing to ecosystem nutrient cycles.
Related Topics
- Peltigerales – the order that includes Collematineae and other suborders such as Peltigerineae.
- Lecanoromycetes – the largest class of lichen‑forming ascomycetes.
- Collema – the type genus, commonly known as “jelly lichens.”
- Peltigera – a well‑known genus within the related suborder Peltigerineae.
- Cyanobacterial photobionts – the photosynthetic partners central to the biology of many Collematineae lichens.
Note: The information presented is based on current taxonomic literature and phylogenetic studies up to 2024.