Black-green lichen on limestone

Black-green lichen on limestone

Observation - Black-green lichen on limestone. Description: Dark black-green thallus growing on limestone gravestone. Lobes visible at outer edge of thallus. Inside outer edge, thallus covered with globular isidia and many tiny plates like small lobes. Possibly Collema crispum .

Dark black-green thallus growing on limestone gravestone. Lobes visible at outer edge of thallus. Inside outer edge, thallus covered with globular isidia and many tiny plates like small lobes. Possibly Collema crispum .