Order: Peltigerales Family: Collemataceae
Species: Leptogium teretiusculum
Photos: Over moss on mortared wall and on limestone. Co. Cork and Co. Kerry, Ireland. Specimen below confirmed by John Douglass
Very small thallus of narrow, dark brown or greyish-brown lobes. Long isidia-like extensions develop at margins and apices forming dense cushions to 1cm diameter. Primary squamules become +/- obscured. Apothecia are very rare, urceolate with thick margins.
Found on mature shaded deciduous trees, also on basic rocks, walls and coastal mossy grassland. Chemical reactions negative.
Similar: Leptogium subtile. Usually very fertile, shorter lobes with none or few isidia-like extensions.
Leptogium teretiusculum January 2010