Malmidea albomarginata is a species of corticolous (bark-dwelling), crustose lichen in the family Malmideaceae.

The type specimen was collected by the authors from the Cerro El Volcán (Miranda) at an elevation of 1,460 m (4,790 ft); there it was found growing in a disturbed tropical mountain rainforest.

Over time, the thallus becomes dull and transforms from grey or greenish-grey to a coralloid granular texture as it ages.

The apothecial discs are flat to slightly convex, with colours varying from ochre to light greyish-brown.

It is distinguished from similar species like Malmidea attenboroughii by differences in apothecia size and the presence of atranorin.