Gabura fascicularis

Gabura fascicularis is a species of jelly lichen in the family Arctomiaceae. It is widely distributed, found across parts of Europe, North Africa, Asia, Australia, and New Zealand. Originally described by Carl Linnaeus in 1767, this small cushion-forming lichen grows primarily on the bark of mature broad-leaved trees such as elm and ash, preferring moist, shaded woodland habitats. The species has a distinctive gelatinous texture when wet and contains cyanobacteria that allow it to fix nitrogen from the atmosphere. Once more widespread, G. fascicularis has declined significantly in many regions due to the loss of old-growth trees and environmental pressures like acid rain, leading to its classification as a near-threatened species in Britain. Molecular studies have revealed that the species may actually comprise two separate groups—one in Europe and another in the Southern Hemisphere—though further research is needed to confirm this distinction.