Belgian botanist Noël Martin Joseph de Necker first described Haematomma ochroleucum in 1771 from a type specimen collected from shaded rocks in the Rheinland-Pfalz region of Germany.

ochroleucum can look very similar to Lecanora thysanophora, but the former species has a shorter, more continuous prothallus which is more uniformly white with thinner hyphae.

[14] In Belgium and Luxembourg, it is found primarily on protected, vertical surfaces on siliceous or sandstone rocks, or on the bark of older beech or oak trees in well-preserved forests.

[16] There, it is found primarily in waterfall spray zones, with fewer colonies on drier vertical rock faces, rocky overhangs, and the trunks of large black cottonwood trees.

[18] Haematomma ochroleucum cannot tolerate significant amounts of sulfur dioxide pollution; it is found only if the mean winter concentrations are less than about 60 μg/m3.

[19] In Ireland, it grows in communities that include Lobaria virens, Nephroma laevigatum, Opegrapha gyrocarpa, Dermatocarpon luridum and Toninia pulvinata.

[13] On the Danish island of Bornholm (in the Baltic Sea), it occurs on vertical rock faces above 10 m (33 ft) high, in association with Ramalina siliquosa, Lecanora atra, and Rhizocarpon constrictum.