This lichen consists of a number of small (up to 3mm diam.) somewhat convex lobes scattered or touching one another. Though the upper surface is brown to olive green it is usually covered in a white to bluish pruina so the lobes appear whitish. The spore producing structures are black dish-shaped apothecia. They can be pruinose but are usually less pruinose than the thallus lobes on which they are formed. Beginning somewhat concave they often grow to become convex. T. aromatica lacks pruina on its lobes. Other species in this genus with which it can be confused are unlikely to occur in Wales.
Photo: R.G. Woods