jellies on the wet bark of old trees
- Size
- Width: 2–10 cm
- Lifespan
- 10–50 years
- Diet
- Photosynthetic. Cyanobacteria fix nitrogen from the atmosphere. Grows on bark of trees, mossy rocks, and rotting logs in damp, shaded forests.
- Habitat
- Grows on the bark of trees, on mossy rocks, and on rotting logs in damp, shaded forests throughout New Zealand. A creature of the wet bark, the damp rock, the places where the water trickles.
- Range
- Found throughout the North and South Islands on bark of trees, mossy rocks, and rotting logs in damp, shaded forests. Most common in the South Island's beech forests and the North Island's western ranges.
- 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.
- Population
- Not Threatened. Collema jelly lichen is common in damp, shaded forests throughout New Zealand, particularly in the South Island's beech forests and the North Island's western ranges.
- Conservation Status
- Not Threatened
- Human Risk
- harmless
- Handling Note
- gelatinous lichen, safe to handle
- Conservation Note
- Native 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 collema jelly lichen from other lichens. Lichens were generally called pūkohu (mosses and lichens) or pukorokoro (crustose lichens). The dark, jelly-like patches would have been noticed. They looked like the skin of an eel. Like the flesh of a sea creature. But no distinct name survives. The collema jelly lichen was sometimes used as a dressing for wounds. The soft, gelatinous lobes were applied to cuts and burns.
The one that looks like a piece of seaweed on the tree has a body that is leafy. Broad, rounded lobes are dark olive-green to blackish when dry. But when it gets wet, it transforms. The lobes swell. Become soft. Gelatinous. Translucent. Like a piece of dark jelly or a wet leaf. It is the lichen of the transformation. The one that briefly remembers what it was like to be alive when the rain comes. The one that looks dead until the water touches it.
What makes it special is the jelly. The collema jelly lichen is one of the few lichens in New Zealand that is gelatinous when wet. Its lobes are thick and rubbery. Filled with a gelatinous substance that absorbs water like a sponge. When it rains, the lichen swells to several times its dry thickness. Becoming soft, pliable, and almost translucent. When it dries out, it shrinks. Becomes dark, brittle, and curled. It is the lichen of the resurrection. The one that comes back to life with every rain. The one that proves that even the driest thing can be revived.
The collema jelly lichen is a foliose lichen. Meaning it grows in flat, leafy lobes. Attached to the substrate at points but not completely stuck down. The lobes are broad and rounded. Often with a wavy or lobed margin. The surface is smooth and shiny when wet. Dull and wrinkled when dry. Under a hand lens, the texture is fascinating. A landscape of tiny bumps and depressions.
Biologically, the collema jelly lichen is a cyanolichen. It contains cyanobacteria (blue-green algae) instead of the green algae found in most other lichens. The cyanobacteria give the lichen its dark colour and its gelatinous texture. They also give it the ability to fix nitrogen from the atmosphere. The collema jelly lichen is a natural fertiliser. Adding nitrogen to the forest canopy.
To find collema jelly lichen is to find the dark, jelly-like patch on the bark. It is dark, rubbery, and alive. A living jelly on the tree. You can touch it when it is wet. Feel the soft, gelatinous texture. It is the lichen of the transformation. The one that briefly remembers what it was like to be alive when the rain comes.