Irish lichens

Anisomeridium biforme

Order: Pyrenulales       Family: Monoblastiaceae

Species: Anisomeridium biforme

Growth type crustose
Photos: On Ash. Ballinagree, Co. Cork, SW Ireland.

A thin white to greyish thallus with small, +/- immersed black perithecia (0.3-0.5mm) leaving pits when they disintegrate. The smaller pycnidia often extrude a whitish jelly containing conidia. Spores 1-septate, 12-16 x 5-7, the septum 1/2 to 1/3 distance from upper end. Microscope photographs below.
Chemical reactions negative.

Common on shaded, smooth-barked trees but easily overlooked.

Similar: Acrocordia gemmata has larger perithecia, 0.5-1mm

Microscope photographs

Anisomeridium biforme April 2012

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