Calopadia cinereopruinosa

Calopadia cinereopruinosa was first scientifically described by lichenologists Frank Bungartz and Robert Lücking in 2011. The type specimen was collected by the first author from San Cristóbal Island, at an elevation of 400 m (1,300 ft); there, in an open Psidium guajava shrubland it was found growing on the bark, wood, and dead twigs of Psidium guajava. The species epithet cinereopruinosa is derived from its grey-black, white-pruinose apothecia.[2]

This lichen species forms a corticolous thallus that can be continuous or marginally dispersed into rounded, confluent patches. The thallus measures up to 30 mm (1+1⁄5 in) across and 20–40 μm thick, displaying a smooth, pale grey to greenish-grey colour. The apothecia are rounded, measuring 0.4–1 mm in diameter and 250–350 μm high, with a grey-black disc and a distinct white pruina. The apothecial margin is thick and prominent when young, also grey-black and white-pruinose.[2]

The ascospores of Calopadia cinereopruinosa are single, oblong to ellipsoid in shape, muriform, and colourless, measuring 45–80 by 15–25 μm. The campylidia are sessile, with a well-developed, hood-shaped, grey lobe that is white-pruinose.[2]

Calopadia cinereopruinosa is found in the Galápagos Islands, mainly on Isla San Cristóbal. It grows in the transition zone towards the humid upper parts of the island. Collections with campylidia have also been found on other islands, mostly in the humid zone. The species typically grows on bark of stems and twigs.[2]