Irish lichens

Opegrapha herbarum

Order: Arthoniales       Family: Roccellaceae

Species: Opegrapha herbarum

Growth type crustose.
Photos: Ardnagashel and Macroom, Co.Cork, Ireland. Identified by Andy Acton and John Douglass

Thin or inconspicuous pale grey, brownish or olive-green thallus.The small, scattered lirellae are usually simple, less frequently branched. Slit-like discs becoming fully open, occasionally +/- green-pruinose. Pycnidia are very rare. Asci are 8-spored, spores 3-septate, 18-25 x 5-8 Ám with thin perispore. Microscope photographs below.

Occurs on acid to basic, smooth, often shady bark. Also found on plant stems (especially brambles) and sandstone.
Chemical reactions negative.


Opegrapha herbarum


Opegrapha herbarum

Microscope photographs
Opegrapha herbarum, microscope photos


Opegrapha herbarum, microscope photos
Opegrapha herbarum March and May 2010

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