Ramalina sarahae was first described in 2018 by the lichenologists Kerry Knudsen, James Lendemer, and Jana Kocourková.

The species epithet honors Sarah Chaney, a retired ecologist and long-time Channel Islands National Park employee who guided various lichenological studies.

[2] The thallus of Ramalina sarahae is caespitose, usually rounded, densely branched, and arises from a single holdfast.

The branches are solid and bifacial with a cortex thickness of 30–40 μm without chondroid strands.

The algal layer is discontinuous, and the medulla consists of dirty white, thin-walled hyphae.