Xanthoparmelia monadnockensis is a species of foliose lichen in the family Parmeliaceae,[2] described by John Elix in 2003.

[1] The thallus of Xanthoparmelia monadnockensis is small-foliose, loosely attached to the substrate, and can grow up to 6 cm (2 in) wide.

The lobes are flat, more or less linear, and range from 0.5 to 1.2 mm wide, featuring more or less dichotomous to irregular branching.

The upper surface is initially yellow-green but quickly darkens, becoming shiny at the tips and developing cracks that lead to an areolate centre.

The lichen is characterised by dense, cylindrical isidia that become richly branched in a coral-like pattern and have dark, fragile tips.