Bryostigma lapidicola, Arthonia muscigena Arthoniaceae
Bryostigma lapidicola (Arthonia muscigena)

Growth type crustose
Chemical results negative. Photobiont chlorococcoid

Usually found on twigs (especially Elder) or tree trunks. Occasional on bryophytes, pine needles, lignum, shaded siliceous rocks and on other lichens. Tolerates suburban conditions.

Patches of tiny, irregularly convex, black apothecia on a thin olive-grey or greyish-brown scurfy-granular thallus. Asci are 8-spored, spores 1-septate, 8-12(-14) x 2.5-4 Ám. The upper cell is shorter and broader than lower cell which often has a slightly pointed apex. Micrographs below.

Similar: Arthonia didyma, photobiont Trentepohlia and wider spores


Bryostigma lapidicola, Arthonia muscigena

Bryostigma lapidicola, Arthonia muscigena

Micrographs
Bryostigma lapidicola, Arthonia muscigena

Bryostigma lapidicola, Arthonia muscigena

Bryostigma lapidicola, Arthonia muscigena
Bryostigma lapidicola (Arthonia muscigena)
Photographs: Broadstone, Dorset. January 2024

All images used are copyright. Please contact me if you find errors.