scaly liverwort with overlapping scales on wet forest rock
- Size
- Width: 2–5 cm
- Lifespan
- 3–7 years
- Diet
- Grows on bark of trees, rocks, and wood in damp, shaded forests. Requires consistent moisture, high humidity, and stable bark surfaces. Forms scaly, leafy mats that cling tightly to the substrate.
- Habitat
- Grows on bark of trees, rocks, and wood in damp, shaded forests. Forms scaly, leafy mats that look like chainmail on the trunk.
- Range
- Found throughout the North and South Islands on bark of trees, rocks, and wood in damp, shaded forests. Most common in lowland and montane forests with high rainfall. Endemic to New Zealand, found nowhere else in the world.
- Endemism
- Endemic
- Main Threats
- None significant. This species is common and widespread. Localised threats include forest clearance, removal of old trees, and climate change reducing forest floor humidity.
- Population
- Not Threatened. Scaly liverwort is common on the bark of native trees throughout New Zealand, particularly in damp, shaded forests. It is endemic to New Zealand, found nowhere else in the world.
- Conservation Status
- Not Threatened
The one that looks like it is wearing chainmail has stems that are creeping and branching, forming dense, leafy mats on the bark. The leaves are tiny, less than a millimetre long, and are arranged in two rows along the stem, overlapping like the scales of a fish or the plates of armour. Each leaf is rounded and concave, with a distinct margin that gives it a scalloped edge. The colour is pale green to yellowish-green, often with a translucent quality. It is the liverwort of the armour plate, the one that looks like it is protecting something soft underneath, the one that is both beautiful and defensive.
What makes it special is the chemistry. Scaly liverwort is one of the most chemically interesting liverworts in New Zealand. It produces a compound called perrottetinene, which is structurally similar to THC, the active compound in cannabis. This compound has psychoactive properties and has been used in traditional medicine and recreation. It is the liverwort of the chemistry set, the one with a secret ingredient, the one that has been known to Māori for centuries.
The leaves are arranged in two rows along the stem, with the lobes overlapping like roof tiles. The leaf margin is entire (smooth) and often has a distinct border of darker cells. The underleaf (amphigastrium) is present but small, often hidden by the overlapping leaves. Under a hand lens, the overlapping scales are visible, a perfect mosaic of green and pale green.
Biologically, the scaly liverwort reproduces by spores, released from capsules on short stalks. It grows on the bark of native trees in damp, shaded forests. It is endemic to New Zealand, found nowhere else in the world, a unique part of our natural heritage.
To find scaly liverwort is to find the tiny, scaly mats on the tree bark. They are pale green, overlapping, and armoured, a living chainmail on the trunk. You need a hand lens to see the overlapping scales, the scalloped edges, the armour for something softer. It is the liverwort of the chemistry set, the one with a secret ingredient, the one that proves that the smallest things can have the biggest secrets.