Lambiella Lithographa Ptychographa Xylographa Xylographaceae is a family of lichen-forming fungi in the order Baeomycetales.

[3] In 1929, British lichenologist Walter Watson published a system of lichen classification and included the genera Lithographa, Ptychographa, and Encephalographa in the Xylographaceae, leaving out Agyrium.

[4] After that, the family was rarely used until it was resurrected in 2015 following molecular phylogenetic analysis of trapelioid fungi in the subclass Ostropomycetidae.

In this analysis, it was determined that trapelioid taxa fall into two major phylogenetic groups; the first group – containing the genera Rimularia, Placynthiella, Trapeliopsis, Trapelia, and Placopsis – are part of the family Trapeliaceae.

[1] These are ascomata with elongated ascocarps that are initially closed but open by means of a longitudinal fissure that exposes the hymenium.