Psoroglaena stigonemoides

Psoroglaena stigonemoides is a species of corticolous (bark-dwelling) lichen in the family Verrucariaceae. It grows primarily on tree bark in humid environments throughout Great Britain, Ireland and parts of Europe. First scientifically described in 1989, it forms distinctive thread-like structures that often break into granular fragments less than a millimetre in height. The species shows a preference for elder trees but can also be found on sycamore, oak, willow and elm, typically in sheltered woodland locations with high humidity. It has a unique biological structure where its fungal component arranges unicellular green algae into rows that resemble filamentous colonies. Unlike many related lichens, it produces pale brown reproductive structures rather than darkly pigmented ones, and is frequently found without these structures. Though widespread across the British Isles, it is often overlooked due to its small size and resemblance to algae or moss protonemata....read more on Wikipedia.