Crocynia Lichen – cottons the damp bark of old trees

cottons the damp bark of old trees

Size: Width: 2–10 cm
Lifespan: 10–30 years
Diet: Photosynthetic. Draws energy from sunlight via algal partner.
Habitat: Grows on the bark of trees, on rocks, and on wood in damp, shaded forests throughout New Zealand. A creature of the damp bark, the shaded trunk, the places where the tree is old and the air is humid. The lichen of the cottony surface, the one that looks soft but is not.
Range: Found throughout the North and South Islands on bark of trees, rocks, and wood in damp, shaded forests. Most common in the South Island's beech forests and the North Island's western ranges. Also found in tropical and temperate regions worldwide.
Endemism: Endemic
Main Threats: None significant. This species is common but under-recorded. Requires damp, undisturbed forests with clean air and stable bark surfaces. Localised threats include forest clearance, air pollution, and bark disturbance.
Population: Not Threatened, though easily overlooked due to its cottony appearance. Crocynia lichen is likely under-recorded in New Zealand, as it requires stable bark surfaces in damp, undisturbed forests. More survey work is needed to understand its true distribution.
Conservation Status: Not Threatened
Human Risk: harmless
Handling Note: foliose/crustose lichen, safe to handle
Conservation Note: Endemic lichen; not assessed by NZTCS as lichens are generally outside the scope of current threat classifications.
Te Ao Māori: No recorded Māori name distinguishes the crocynia lichen from other lichens. Lichens were generally called pūkohu (mosses and lichens) or pukorokoro (crustose lichens). The cottony fuzzy patches on the bark would have been noticed. They looked like the wool of a sheep like the hair of a creature but no distinct name survives. The crocynia lichen was sometimes used as a dressing for wounds. The soft-looking fibres were applied to cuts to stop bleeding though they were not as effective as other materials.

The one that looks like it is wearing a fuzzy sweater has a body that is a thin crusty layer on the bark but it is not smooth like other crustose lichens. It is covered in a dense mat of tiny cottony fibres like a piece of soft felt or a scrap of cotton wool. The colour is pale greyish-white to pale greenish-grey. It looks soft looks touchable looks like it would be pleasant to stroke. But it is not. It is scratchy brittle and slightly unpleasant to touch. It is the lichen of the false promise the one that looks soft but is not. What makes it special is the deception. Crocynia lichen is one of the most deceptive lichens in New Zealand. Its cottony surface looks soft and inviting like a piece of felt or a soft moss. But when you touch it you find that it is rough and scratchy made of brittle fibres that break at a touch. It is the lichen of the false invitation the one that tricks you into touching it and then disappoints the one that proves that appearances can be deceiving. The crocynia lichen is a crustose lichen meaning it grows flat on the bark or rock like a crust of paint but with a distinctive cottony texture. Its body is a mat of tiny branched fibres (hyphae) that spread across the surface. The colour is pale often with a greenish tint from the algae inside. Under a hand lens the fibres are visible a tangled web of white threads. Biologically the crocynia lichen is a partnership a fungus and an alga living together. The fungus provides structure and protection. The alga provides food through photosynthesis. The cottony fibres are the fungal hyphae loosely woven together to form a protective layer over the algae. To find crocynia lichen is to find the cottony patch on the bark. It is pale fuzzy and deceptive a false promise on the tree. You will want to touch it. You will think it will be soft. You will be wrong. It is the lichen of the cottony surface the one that looks soft but is not the one that teaches a lesson about not judging by appearances.