Lichens are brightly coloured through pigmentation. Rust-coloured species, such as Acarospora sinopica are often assumed to contain ‘rust’, i.e. hydrated iron oxides, though analysis has rarely been carried out. This lichen does not react with chemicals commonly used to identify lichens in the field.

The lichen bodies (thalli) are deep rust-red and form cracked, crazy pavement-like, patches up to 10 cm across. Sometimes they form lines in cracks on rocks, or are scattered as tiny 'islands' amongst other lichens.


Fruiting bodies are

  • volcano-like when well developed
  • usually abundant 
  • 0.4 - 0.6 mm in diameter
  • clustered (2 - 5) 
  • capped by 
    • a darker brown
    • wart-like or
    • wrinkled disc

Spores are tiny, approx 3 microns long about 1000 would fit on a pin-head.

Asci contain more than 100-spores.