shields the windy alpine rocks
- Size
- Width: 5–15 cm
- Lifespan
- 20–100 years
- Diet
- Symbiotic partnership. Fungus provides structure. Alga provides food via photosynthesis. Requires clean air, stable rock surfaces, and good light.
- Habitat
- Exposed, windy locations from sea level to alpine zone on rocks and boulders. Where wind blows, rain falls, and rock is cold and hard.
- Range
- Found throughout North and South Islands on rocks and boulders in exposed, windy locations. Most common in South Island high country and North Island volcanic plateau.
- Endemism
- Native
- Main Threats
- None significant. Localised threats include quarrying of rock outcrops, air pollution, and climate change affecting rock surface conditions.
- Population
- Not Threatened. Common and widespread on rocks in exposed, windy locations from coast to mountains. On native and introduced rock types throughout New Zealand.
- Conservation Status
- Not Threatened
- Human Risk
- harmless
- Handling Note
- foliose 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 hammered shield lichen from other lichens. Lichens were generally called pūkohu or pukorokoro. Hammered texture would have been noticed. Looked like surface of carved stone. Like mark of tool. No distinct name survives. Sometimes used as dye. Grey-green pigment extracted to colour fibres. Though not as vibrant as yellow sunburst lichen. Still grows on mountain rocks and coastal boulders.
Wind blows against it constantly. Parmelia saxatilis looks like dented metal. Hammered shield lichen has flat, leafy, grey body. Pale grey to bluish-grey. Sometimes with hint of green. Lobes are broad and rounded. Spreading across rock like map of foreign country. But surface is story. Covered in network of raised, white lines and depressed, dark pits. Pattern looks exactly like hammered metal or wrinkled leather. Lichen that has been beaten into shape.
What makes it special is texture. One of most distinctive lichens in New Zealand. Surface is not smooth like common grey shield. It is wrinkled, pitted, and ridged. Landscape of tiny mountains and valleys. Raised ridges are called pseudocyphellae. Tiny breathing holes appearing as white lines. Pits are bare spots where algal layer is thin. Together create pattern looking like thumbprint or hammered copper.
Underside is black. Covered in dense mat of rhizines. Tiny, root-like structures anchoring it to rock. Rhizines so thick they form felt-like pad. Gripping stone with strength seeming impossible. Try to peel it off and you will fail. Lichen that does not let go.
It is a partnership. Fungus and alga living together. Grows slowly. Few millimetres per year. Large patch may be decades old. Lichen of patience. Takes its time.
To find hammered shield lichen is to find dented metal on rock. Grey, flat, textured. Living pattern on stone. Run finger over it. Feel ridges, pits, hammered surface. Lichen of boulder. Looks like it has been beaten into shape. It carries on regardless.