The thallus of this species forms dispersed or sometimes confluent patches that are slightly inflated due to a strong encrustation with calcium oxalate crystals.

These patches are whitish to silvery grey, with a smooth to irregularly rough and wrinkled surface texture and a narrow, crystal-free, greenish margin.

The thallus of Calenia bullatinoides is marked by a slight inflation, a feature caused by the accumulation of calcium oxalate crystals, and for its smooth to irregularly rugose surface.

[2] Hyphophores, specialised asexual spore-producing organs formed on the crystalline thallus patches, are short, setiform (bristle-like), and have an apically darkened tip.

Other species such as Gyalectidium ciliatum and Bullatina aspidota show superficial similarities but differ significantly in their hyphophores, asci, and thallus morphology.