Order: Peltigerales       Family: Collemataceae Species: Arctomia fascicularis (Collema fasciculare) Growth type foliose. Photos: Killarney National Park, Co. Kerry, SW Ireland. Thallus forms small pulpy cushions, very swollen and easily loosened when wet. Lobes often indistinct, short, wrinkled, sometimes lobulate. Apothecia are abundant and often cover the thallus with flat discs, their margins thick and +/- wrinkled. Asci (6-)8 spored, spores 9-17 septate, 50-90 x 4-5 µm, worm-like and spirally twisted in the asci. Micrograph below. Occurs among moss on trunks of mature trees, usually Ash and Hazel, in western oceanic woodlands. Chemical reactions negative.

Micrograph

Arctomia fascicularis (Collema fasciculare) November 2009