the yellow-spotted lichen of NZ's old beech trunks
- Size
- Width: 5–20 cm
- Lifespan
- 20–100 years
- Diet
- Grows on bark of trees, mossy rocks, and rotting logs in damp, undisturbed forests. Requires clean air, stable bark surfaces, and high humidity. Tolerates shade and moisture but cannot survive prolonged drought.
- Habitat
- Grows on the bark of trees, on mossy rocks, and on rotting logs in damp, undisturbed forests throughout New Zealand. A creature of the deep bush, the wet gully, the places where the moss hangs thick and the air is heavy with moisture. Found from sea level to the montane zone, particularly in humid, sheltered locations where the forest has been standing for centuries. The lichen of the leafy complexity, the one that hides bright secrets on its underside.
- 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. This genus is particularly diverse in New Zealand, with many endemic species.
- Endemism
- Endemic
- Main Threats
- None significant. This species is common and widespread in damp, undisturbed forests. Localised threats include forest clearance, air pollution, and climate change reducing forest floor humidity.
- Population
- Not Threatened. Pseudocyphellaria is a genus of lichens that is particularly diverse in New Zealand, with many endemic species. This species is common in damp, undisturbed forests throughout the country.
- Conservation Status
- Not Threatened
The one that looks like a leafy vegetable has a body that is large, leafy, and complex, with broad, overlapping lobes that spread across the bark or rock like a crumpled piece of lettuce. The upper surface is pale greyish-green to brownish-green when dry, bright green when wet. It is covered in tiny, white dots called pseudocyphellae, breathing holes that give the genus its name. But the real surprise is on the underside.
What makes it special is the underside. The pseudocyphellaria lichen has a bright yellow or orange underside that is completely hidden when the lichen is attached to the bark. If you gently lift a lobe, you will see a flash of bright colour, yellow, orange, or sometimes pale cream. The underside is covered in a dense mat of tiny, root-like structures (rhizines) that anchor it to the bark. It is the lichen of the hidden secret, the one that keeps its bright side facing the tree, the one that makes you want to peek underneath.
The pseudocyphellaria lichen is a foliose lichen, meaning it grows in flat, leafy lobes that are attached to the substrate at points but not completely stuck down. The lobes are broad and rounded, often with a wavy or ruffled margin. The upper surface is often wrinkled or pitted, with a network of raised veins. Under a hand lens, the pseudocyphellae are visible as tiny white dots scattered across the surface.
Biologically, the pseudocyphellaria lichen is a partnership, a fungus, a green alga, and a cyanobacterium living together. The fungus provides structure and protection. The green alga provides food through photosynthesis. The cyanobacterium provides nitrogen through fixation. It is a three-way partnership, a tiny ecosystem on the bark of an old tree, a miniature world of cooperation and mutual dependence.
To find pseudocyphellaria lichen is to find the leafy patch on the bark. It is pale, complex, and leafy, a living vegetable on the tree. You can gently lift a lobe and see the bright underside, the hidden secret. It is the lichen of the hidden surprise, the one that keeps its bright side facing the tree, the one that proves that the most interesting things are often hidden from view.