Eilifdahlia sergeyana

Eilifdahlia sergeyana is a species of saxicolous (rock-dwelling), crustose lichen in the family Teloschistaceae. It is endemic to Kangaroo Island in South Australia. The lichen thallus has an uneven and scaly texture, forming patches up to 40 mm wide in dull greenish-grey or brownish-grey. Its fruiting bodies (apothecia) are orange to yellow, with a biatorine structure, and range from 0.5 to 1 mm wide. These apothecia have a matte surface and a cup-shaped margin containing golden-yellow crystals. The paraphyses within are slender and branched, and the asci contain ellipsoid spores.