askeglye

Askeglye (Collema leptaleum)

Askeglye is a foliose lichen species characterized by its thin, leaf-like thallus with a distinctive gelatinous texture when moist. The lichen forms small, irregularly lobed structures that appear dark olive-green to blackish when wet and become pale greyish-brown upon drying. Like other members of the Collema genus, askeglye contains cyanobacteria as its photosynthetic partner, enabling it to fix atmospheric nitrogen and contribute to soil formation processes in its ecosystem.

This critically endangered lichen has an extremely limited geographic distribution, known from only a few locations in Northern Europe, particularly in Scandinavia. Askeglye typically grows on calcareous substrates, including limestone rocks and mortar in old stone walls, preferring areas with stable moisture conditions and minimal disturbance.

The species faces significant threats from habitat degradation and loss. Urban development and modernization of historic stone structures have eliminated many potential growing sites. Air pollution, particularly nitrogen deposition, alters the chemical composition of its preferred substrates, making them unsuitable for colonization. Climate change may also affect the delicate moisture balance required for the lichen's survival.

Current conservation efforts remain limited due to the species' recent recognition and poorly understood ecology. Some European countries have initiated lichen monitoring programs that include Collema species, though specific measures targeting askeglye are minimal.

The outlook for askeglye remains precarious. Without targeted conservation intervention and habitat protection, this species faces continued decline. Its extremely restricted range makes it particularly vulnerable to local extinctions from individual site disturbances.