Caloplaca maculata

Caloplaca maculata is a species of lichenized fungus endemic to New Zealand.

Systematics
Caloplaca maculata was first described by lichenologist David Galloway in 2004; the type specimen was collected from a rocky shoreline on Chatham Island, the largest island in an archipelago off New Zealand's South Island. The genus name Caloplaca means "beautiful patches", while the species name maculata is derived from the Latin maculātus, meaning "to cover with stains" or "to mark with coloured patches".

Description
Caloplaca maculata is a crustose lichen which grows in irregular rosettes measuring 1 – in diameter. The thallus (the vegetative body of the lichen) is pale greenish-white when wet and greyish-white when dry, without a noticeable. Its surface is areolate, broken into angular polygons separated by deep cracks. The disc-like apothecia (the lichen's fruiting bodies) are large and conspicuous: orange when dry and clear yellow when wet. These are sessile – attached directly at their base to the thallus without a stalk.

Chemistry
In spot tests, the thallus is and the apothecia are K+, turning a reddish purple. Secondary metabolites include parietin.

Habitat and range
Although Caloplaca maculata was initially thought to be endemic to Chatham Island, it has since been found on other islands in the same archipelago, and on New Zealand's South Island. It is saxicolous, growing on tuffaceous rock outcrops and basalt, typically in more sheltered locations along the coast. It has been found growing amongst other lichen species, including Caloplaca litoralis, Dufourea ligulata, Myriolecis dispersa, Pertusaria graphica, Physcia caesia and members of the genera Amandinea, Buellia and Caloplaca.