scales rough bark of damp forest trees

Size
Width: 2–8 cm
Lifespan
5–15 years
Diet
Obtains nutrients via photosynthesis. Requires consistent moisture and high humidity. Grows on bark, rocks, and wood in shaded forests.
Habitat
Bark of trees, rocks, and wood in damp, shaded forests where tree bark is rough, stable, and air remains consistently humid.
Range
Found throughout the North and South Islands on bark of native trees, rocks, and wood in damp, shaded lowland and montane forests.
Endemism
Endemic
Main Threats
None significant. Localised threats include forest clearance, removal of old rough-barked trees, and climate change reducing humidity.
Population
Not Threatened. Common on bark of native trees, rocks, and wood in damp, shaded forests throughout New Zealand.
Conservation Status
Not Threatened
Human Risk
harmless
Handling Note
common liverwort, safe to handle
Conservation Note
Endemic liverwort; not assessed by NZTCS as bryophytes are generally outside the scope of current threat classifications.
Te Ao Māori
No recorded Māori name distinguishes the porella liverwort from other liverworts. Liverworts were generally called "pūkohu" (mosses and lichens). The glossy, layered mats on the bark would have been noticed. They looked like the skin of a fish. Like the scales of a serpent. But no distinct name survives. This liverwort was not used as a medicine or a dye. It was too small. Too hidden. Too easy to overlook. It was simply part of the forest. A quiet, glossy presence on the bark.
It has been polished, this one. A liverwort that shines. Porella liverwort spreads across tree bark in glossy, layered mats. Each leaf overlapping the next like roof tiles. The surface shines dark green to olive-brown. Catching light with a sleek, almost metallic gleam. A plant that looks like it has been waxed. The gloss comes from a thick cuticle. A waxy protective layer that stops the leaf from drying out. This is one of the glossiest liverworts in New Zealand. The kind of finish that might be expected on a well-waxed car. Or a piece of furniture buffed to mirror brightness. A plant that wears a coat of wax. Leaves arrange in two rows along a creeping, branching stem. The upper lobes lie flat against the bark. The lower lobes fold underneath. Overlap is so tight that the stem disappears entirely from view. Leaf margins are smooth. Often bordered by darker cells. A plant that hides its own stem. This liverwort hugs the bark like a second skin. Flowing over every contour of the trunk. It seems to want to become part of the tree itself. Reproduction happens by spores released from capsules on short stalks. But the real show is visual. A continuous, glossy sheen that wraps around rough bark like it has been waxed and buffed by an invisible hand. To find porella liverwort is to find that shiny, layered mat on tree bark. Dark green. Reflective. Hugging tight. The bark is rough. The liverwort spreads across it. Glossy and smooth. A second skin on the trunk. It does not need to be tall. It does not need to be big. It just shines. That is enough. Populations are not threatened. Common on bark of native trees. Rocks. And wood in damp, shaded forests throughout New Zealand. Localised threats include forest clearance. Removal of old rough-barked trees. Climate change reducing humidity.