Order: Peltigerales       Family: Collemataceae Collema polycarpon Growth type foliose. Photos: On limestone. Black Head, the Burren, Ireland. Identification needs confirming 'Cushion like' thallus of numerous thick, +/- contorted, +/- radiating lobes, usually acending at centre. Numerous terminal apothecia, isidia are absent. Occurs on exposed, hard, moist limestone, often found with Collema multipartum. Most frequent in the Burren and west and central Ireland. Chemical reactions negative.

Collema polycarpon. Black Head, the Burren. April 2009