the tall haircap moss of NZ's wet forest and bogs
- Size
- Height: 5–15 cm
- Lifespan
- 5–10 years
- Diet
- Grows in damp, acidic soils in bogs, forest clearings, and stream banks. Requires consistent moisture, acidic soil, and good light. Tolerates poor soils, sun, and moderate drought. One of the most widespread mosses in the world.
- Habitat
- Grows in damp, acidic soils throughout New Zealand, from sea level to the subalpine zone, in bogs, forest clearings, and along stream banks. A creature of the wet ground, the open forest, the places where the soil is poor and the sun can reach. Forms upright, bristly colonies that look like a miniature forest if you shrink your expectations enough.
- Range
- Found throughout the North and South Islands in damp, acidic soils in bogs, forest clearings, and stream banks. Most common in lowland and montane areas with consistent moisture. Also found worldwide in temperate and cold regions.
- Endemism
- Native
- Main Threats
- None significant. This species is one of the most widespread mosses in the world. Localised threats include drainage of bogs and wetlands, habitat loss from land development, and climate change affecting soil moisture.
- Population
- Not Threatened. Common haircap moss is one of the most widespread mosses in the world, found on every continent except Antarctica. In New Zealand, it is common in damp, acidic habitats throughout the country.
- Conservation Status
- Not Threatened
The one that looks like a tiny forest of green spears has stems that are upright and unbranched, reaching 5 to 15 centimetres in height. The leaves are long, narrow, and pointed, arranged in a dense spiral around the stem. They are stiff and bristly, sticking out at right angles like the bristles of a brush. When you look down at a colony of haircap moss, you see a carpet of green points, a miniature forest that would be a forest if you were the size of an ant. It is the moss of the miniature world, the one that passes for a forest if you shrink your expectations enough.
What makes it special is the structure. The common haircap moss is one of the most structurally advanced mosses in New Zealand. Unlike most mosses, which are only a few cells thick, the haircap moss has a primitive vascular system, specialised cells that transport water and nutrients up the stem. This allows it to grow taller than most other mosses, standing upright like a tiny tree. It also has a cuticle, a waxy layer that prevents water loss, and leaves that are not just one cell thick but have distinct midribs. It is the moss that thinks it is a plant, the one that reached for the sky before there were trees.
The leaves are covered in microscopic, upright plates called lamellae, tiny green fins that run along the upper surface of the leaf. These lamellae increase the surface area for photosynthesis, allowing the moss to capture more light. They also help trap moisture, creating a humid microclimate around the leaf. Under a microscope, the lamellae are beautiful, rows of tiny green fins standing upright like a miniature forest on the leaf itself.
Biologically, the common haircap moss reproduces by spores, released from capsules at the tips of tall, reddish-brown stalks. The capsules are square-shaped when young, with a hairy calyptra (cap) that gives the moss its name. The spores are tiny, carried by the wind to new locations.
To find common haircap moss is to find the tiny forest on the ground. It is upright, bristly, and green, a miniature world at your feet. You can run your finger over the tips and feel the bristles, the points, the texture of a tiny forest. It is the moss of the miniature world, the one that passes for a forest if you shrink your expectations enough, the one that proves that size is not the only measure of grandeur.