the grey lobed lichen of NZ's lowland broadleaf bark
- Size
- Width: 5–15 cm
- Lifespan
- 10–50 years
- Diet
- Grows on bark of trees, rocks, and wood in damp, shaded forests. Requires clean air, stable bark surfaces, and high humidity. Forms wrinkled, shield-like lobes that are pale greyish-green to brownish-green.
- Habitat
- Grows on the bark of trees, on rocks, and occasionally on old fence posts throughout New Zealand. A creature of the branch and the boulder, the forest and the farm. Found from sea level to the montane zone, particularly in open, sunny locations where the bark is rough and the air is clean. The lichen of the weathered face, the one that looks like it has seen things.
- 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 temperate regions worldwide.
- Endemism
- Native
- Main Threats
- None significant. This species is common and widespread in damp, shaded forests. Localised threats include forest clearance, air pollution, and climate change reducing forest floor humidity. Classified as Not Threatened.
- Population
- Not Threatened. This is a common and widespread lichen in New Zealand, particularly in the North Island and the northern South Island. It grows on the bark of native and introduced trees, on rocks, and on fence posts.
- Conservation Status
- Not Threatened
The one that looks like an old man's face has a body that is flat, leafy, and grey, pale grey to bluish-grey, sometimes with a hint of green. The lobes are broad and rounded, spreading across the bark like a map of a foreign country. But the surface is the story. It is covered in a dense network of wrinkles, ridges, and folds, a landscape of tiny mountains and valleys. It is the lichen that has seen a hundred years of sun and rain, the one that wears its age on its surface, the one that looks like it has stories to tell.
What makes it special is the wrinkles. The wrinkled shield lichen is one of the most textured lichens in New Zealand. Its surface is not smooth like the common grey shield or puffed like the velvet shield. It is wrinkled, deeply wrinkled, with ridges and folds that run in every direction. The wrinkles are most visible when the lichen is dry, when the surface contracts and the ridges stand out. When wet, the lichen swells and the wrinkles become less prominent. It is the lichen of the changing face, the one that looks different in the rain, the one that reminds you that nothing stays the same.
The lobes are broad and rounded, often with small, scattered white spots on the surface. The margins are entire or slightly wavy, often with small, powdery granules (soredia) that break off and grow into new lichens. The underside is black and covered in a dense mat of rhizines, tiny, root-like structures that anchor it to the bark.
Biologically, the wrinkled shield lichen is a partnership, a fungus and an alga living together. The fungus provides structure and protection. The alga provides food through photosynthesis. The wrinkles are an adaptation to dry conditions, allowing the lichen to expand and contract with changes in moisture without cracking.
To find wrinkled shield lichen is to find the wrinkled grey patch on the bark. It is flat, leafy, and wrinkled, a living face on the tree. You can run your finger over the surface and feel the ridges, the folds, the texture of age. It is the lichen of the weathered face, the one that looks like it has seen things, the one that proves that age is not something to hide, but something to wear with pride.