Rhizocarpon reductum Rhizocarpaceae
Rhizocarpon reductum

Growth type crustose
Chemical reactions variable, usually K+ yellow, C-, P+ orange.
Rarely K-, P- or K+ red, P+ orange

Pioneer species on siliceous pebbles, rocks and tombstones.

Grey to mousey-brown thallus, cracked-areolate with a thin black prothallus. The black apothecia become seesile with thin, persistent margins. Epithecium dark green to greyish-brown. Spores colourless, becoming muriform with 8-13 cells, 20-35 x 10-15 Ám. Micro photos below.

Similar: Rhizocarpon petraeum


Rhizocarpon reductum

Rhizocarpon reductum

Rhizocarpon reductum

Microscope photographs
Rhizocarpon reductum

Rhizocarpon reductum
Rhizocarpon reductum
On pebbles and gravestone. Studland and Lytchett Matravers, Dorset. March 2013, December 2016

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