kidneys out on the damp shaded tree bark

Size
Width: 2–5 cm
Lifespan
3–7 years
Diet
Photosynthetic. Draws energy from sunlight. Requires consistent moisture, high humidity, and stable bark surfaces.
Habitat
Grows on bark of trees, rocks, and rotting logs in damp, shaded forests. Forms distinctive, kidney-shaped, bright green fronds.
Range
Found throughout North and South Islands on bark of trees, rocks, and wood. Most common in lowland and montane forests with high rainfall. Also found in temperate regions worldwide.
Endemism
Endemic
Main Threats
None significant. Common and widespread. Localised threats include forest clearance, removal of old trees, and climate change reducing humidity.
Population
Not Threatened. Common in damp, shaded forests throughout New Zealand. Particularly on bark of native trees and rotting logs. Distinctive and easy to recognise.
Conservation Status
Not Threatened
Human Risk
harmless
Handling Note
native filmy fern, delicate fronds handle with care
Conservation Note
Endemic fern; widespread in humid forests throughout New Zealand.
Assessment
NZTCS Vascular Plants (2023)
Te Ao Māori
No recorded Māori name distinguishes trichomania liverwort from other liverworts. Liverworts were generally called pūkohu or grouped with other small, damp-loving plants. The tiny, kidney-shaped fronds on the bark would have been noticed. They looked like the kidneys of a creature. Like the shape of a shell. No distinct name survives. It was sometimes used as medicine. The fleshy fronds were applied to wounds to stop bleeding. Perhaps because of their kidney-like shape.
It is not rare. Hymenophyllum nephrophyllum looks like a tiny kidney. Its fronds are undivided, kidney-shaped, and fleshy. A single, rounded leaf attached to a short stalk. The fronds are bright green and translucent. With a glossy surface that catches the light. They are arranged in loose clusters on the bark. Each one a tiny green kidney. It is the liverwort of the organ shape. The one that looks like it belongs inside a body rather than on a tree. The one that is both familiar and strange. What makes it special is the shape. Trichomania liverwort is one of the most distinctive liverworts in New Zealand. Its kidney-shaped fronds are unlike anything else in the plant kingdom. They look like tiny kidneys. Or small, fleshy leaves. The shape is a blurring of the line between fern and something older. Something more primitive. It is the liverwort of the ancient shape. The one that looks like it has been around since the time of the first plants. The one that is a living fossil. The fronds are undivided. A single, rounded blade attached to a short stalk. The margin is entire. Smooth. Often slightly wavy. The surface is glossy and translucent. With a network of veins visible when held up to the light. The colour is a bright, vibrant green. Under a hand lens, the veins are visible. A delicate network of lines running through the translucent tissue. Biologically, it reproduces by spores released from capsules on short stalks. The capsules are often hidden among the fronds. The spores are tiny. Carried by the wind to new locations. To find trichomania liverwort is to find the tiny green kidneys on the bark. They are bright, glossy, and kidney-shaped. A living organ on the tree. You can see the veins. The translucent surface. The ancient shape. It is the liverwort of the blurry line. The one that blurs the line between fern and something older. The one that proves that the oldest designs are often the most elegant. It carries on regardless of classification.