Species: Collema fuscovirens
Photos: On limestone. The Burren, Co. Clare, Ireland.
Leathery, deep-lobed thallus with dark olive-green to blackish lobes, paler below. Swelling little when wet but slightly transluscent. Apothecia sparse or frequent, margins smooth or isidiate. Thinner lobes and smaller isidia than C. auriforme.
Occurs on sunny limestone outcrops and dry stone walls.
Chemical reactions negative.
Similar: C. auriforme. Lobes very swollen when wet.
Collema fuscovirens March and July 2009