Haematomma is a genus of crustose lichens established by Abramo Bartolommeo Massalongo in 1852.

[2] It is the sole genus in the Haematommataceae,[3] a family circumscribed by Josef Hafellner in 1984.

[4] Commonly called bloodstain lichens,[5] the species assigned to this genus are widely distributed in tropical and temperate areas.

[6] The genus name Haematomma means "bloody eye", a reference to the color of the lichen's apothecia.

[7] As of September 2021[update], Species Fungorum accepts 22 species in the genus Haematomma:[8]