the grey beard lichen draping NZ's subalpine trees
- Size
- Length: 5–30 cm
- Lifespan
- 10–50 years
- Diet
- Grows on branches and trunks of trees in damp, undisturbed forests. Requires clean air, stable bark surfaces, and high humidity. Sensitive to air pollution. Hangs from branches like a tangled beard, pale greyish-green to yellowish-green, branching and re-branching into a dense, shrubby mass.
- Habitat
- Hangs from the branches of trees throughout New Zealand, particularly in damp, undisturbed forests. A creature of the branch and the twig, the high canopy and the forest edge. Found from sea level to the subalpine zone, in humid, sheltered locations where the air is clean and the moss grows thick. The lichen of the tangled beard, the one that looks like the forest forgot to shave.
- Range
- Found in the South Island's beech forests and the North Island's western ranges. Most common in damp, undisturbed forests with high rainfall and clean air. Also found in temperate and cold regions worldwide.
- Endemism
- Native
- Main Threats
- None significant. This species is common and widespread in clean-air areas. Localised threats include forest clearance, air pollution, and climate change reducing forest floor humidity.
- Population
- Not Threatened. This is a common and widespread lichen in New Zealand, particularly in the South Island's beech forests and the North Island's western ranges. It grows on the branches and trunks of native and introduced trees.
- Conservation Status
- Not Threatened
The one that looks like the forest has grown a beard has a body that is pale greyish-green, with long, hair-like strands that hang from the branches like a tangled beard. The strands are branching and flexible, often reaching 10 to 30 centimetres in length. They are finer and more tangled than the usnea beard lichen, forming a dense, matted curtain on the branches. It is the lichen of the unshaven forest, the one that makes the trees look like old men, the one that gives the forest a face.
What makes it special is the tangles. The old man's beard lichen is one of the most tangled lichens in New Zealand. Its strands are thin and wiry, branching repeatedly and intertwining with each other to form a dense, matted mass. It looks like a ball of yarn, like a tangled fishing net, like the beard of a man who has not shaved for a hundred years. It is the lichen of the messy hair, the one that cannot be combed straight, the one that is beautiful in its chaos.
The strands are elastic and tough, not brittle like other fruticose lichens. They can be stretched and twisted without breaking. The central core is a dense cord of fungal hyphae, surrounded by a layer of algae and an outer cortex. It is a master of flexibility, a plant that bends without breaking, a lichen that can survive the wind and the rain.
Biologically, the old man's beard lichen is a partnership, a fungus and an alga living together. The fungus provides structure and protection. The alga provides food through photosynthesis. The old man's beard lichen is also a bioindicator. It is sensitive to air pollution, particularly sulphur dioxide. In polluted air, it dies. It is the canary of the canopy, the one that tells us whether the air is healthy.
To find old man's beard lichen is to find the tangled hair on the branch. It is pale, matted, and soft, a living beard on the tree. You can run your fingers through the strands and feel the tangles, the knots, the messy texture. It is the lichen of the unshaven forest, the one that looks like the forest forgot to shave, the one that proves that the forest has a personality.