Heteroplacidium compactum

About

Heteroplacidium compactum is a species of areolate, crustose lichen in the family Verrucariaceae. It has a cosmopolitan distribution. It is a lichenicolous lichen, growing as a facultative parasite on other lichens, typically on non-calcareous rock. It has rod-shaped (bacilliform) conidia measuring 5–7 μm long, and ascospores that are 11–18 by 8–10 μm. Heteroplacidium zamenhofianum is a closely related species distinguished by having perithecia situated in the algal layer, and smaller ascospores with a more narrow ellipsoid shape.

Summary from Wikipedia