the stringy beard lichen of NZ's old forest branches
- Size
- Length: 5–20 cm
- Lifespan
- 10–50 years
- Diet
- Grows on bark of trees, rocks, and wood in open, sunny locations with clean air. Requires clean air, stable bark surfaces, and good light. Forms beard-like, pendulous, pale greyish-green fronds that hang from branches.
- Habitat
- Hangs from branches of trees in damp, undisturbed forests. Found from sea level to the subalpine zone, in humid, sheltered locations where the air is clean. The lichen of the hanging hair, the one that gives trees a slightly haunted look.
- Range
- Found throughout the North and South Islands on bark of trees in open, sunny locations with clean air. Most common in the South Island's beech forests and the North Island's western ranges. Absent from urban areas due to air pollution sensitivity.
- Endemism
- Native
- Main Threats
- None significant in clean-air areas. This species is sensitive to air pollution. Localised threats include air pollution, removal of old trees, and bark disturbance. Absent from urban and industrial areas with poor air quality.
- 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 an old man's 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 20 centimetres in length. They are covered in tiny, fuzzy projections called fibrils, giving them a soft, hair-like texture. It is the lichen of the haunted tree, the one that makes the forest look old and wise, the one that seems to whisper when the wind blows.
What makes it special is the shape. The usnea beard lichen is a fruticose lichen, meaning it grows upright but then hangs down, like a pendant or a curtain. Its strands are attached to the bark at a single point and then hang free, swaying in the wind. It looks like Spanish moss, like the beard of a wizard, like the hair of a ghost. It is the lichen of the hanging garden, the one that turns the tree into a living sculpture, the one that makes you think of Merlin and magic.
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 usnea 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 usnea 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, the one that vanishes when we poison the sky.
To find usnea beard lichen is to find the hanging hair on the branch. It is pale, tangled, and soft, a living beard on the tree. You can run your fingers through the strands and feel the soft, fuzzy texture. It is the lichen of the haunted tree, the one that makes the forest look old and wise, the one that proves that the cleanest air holds the strangest beauty.