This specimen was collected at an altitude of 700 m (2,300 ft), situated on sandstone rocks beside an old road that runs adjacent to an open Eucalyptus woodland.

The upper surface is white to off-white, dull, and appears crystalline or spotted due to the incorporation of silica.

The medulla is white, contains calcium oxalate (as indicated by a positive sulphuric acid reaction), and does not change colour when stained with iodine.

[1] The apothecia, or fruiting bodies, are 0.1–0.4 mm wide, lecideine in type, and can be separate, broadly attached, with a black, non-powdery, and either weakly concave or convex disc.

The ascospores are of the Buellia type, 1-septate, brown, ellipsoid, measuring 9–13 by 5–7 μm, and older spores are constricted at the septum; the outer spore-wall is microrugulate.

At the time of its original publication, Buellia kowenensis was known only from its type collection in Kowen Forest, Australian Capital Territory.