Fissurina simplex

Fissurina simplex is a species of corticolous (bark-dwelling), crustose lichen in the family Graphidaceae. Found in India, it was formally described as a new species in 2012 by Bharati Sharma, Pradnya Khadilkar, and Urmila Makhija. The type specimen was collected from an evergreen forest in Silent Valley National Park (Kerala); it has also been recorded from a humid deciduous forest in Karnataka.

The lichen has a brown, glossy, and cracked thallus that is delimited by a black region at its periphery. The ascomata are, 0.5–1.5 mm long, , usually straight (sometimes curved) and the same colour as the thallus. They are immersed to slightly raised, arising as a swelling that then cracks and gapes, and have a terminally acute structure of subcontexta-type. The are hyaline,, and measure 70–78 by 20–25 μm with a thin.

Fissurina simplex contains two secondary metabolites (lichen products): stictic acid and hypostictic acid.