H. annamariae H. pallescens H. seaveyorum H. siamensis H. sipmanii Heiomasia is a genus of corticolous (bark-dwelling), crustose lichens in the family Graphidaceae.

The genus was circumscribed in 2010 by Matthew Nelsen, Robert Lücking and Eimy Rivas Plata, with Heiomasia sipmanii assigned as the type species.

[2] Molecular phylogenetic analysis showed that it, along with another then-undescribed species, H. seaveyorum, formed a clade with a distinct lineage in the Graphidaceae, and so Heiomasia was created to contain them.

[1] Heiomasia species have pale green to whitish thalli that are effuse (spread out) and byssoid (wispy, like cotton), and often have a white prothallus.

[1] Morphologically, Heiomasia resembles species in Cryptothecia, Herpothallon, and Dichosporidium, but those genera are in the order Arthoniales and are not closely related.