Aulaxinella lichens form a continuous layer (
thallus) on their , with a distinctive dark brown border () around the edges. Their reproductive structures (
apothecia) appear crater-like, emerging from the surface with a prominent dark rim that lacks algal cells. The central part of these structures is brownish in colour. A distinctive feature of the genus is its specialised reproductive structures called , which appear in groups on patches of the lichen that lack algal cells. These structures are black and bristle-like with blunt tips. They produce unique branching threads () that emerge from their tips in 3–5 separate bunches, forming chains of small, sometimes divided segments. ==Species==