Irish lichens

Arthonia ilicana

Order: Arthoniales       Family: Arthoniaceae

Species: Arthonia ilicina

Growth type crustose
Photos: On Holly. Ballingeary, Co. Cork, SW Ireland.

The immersed creamy-yellow thallus is usually surrounded by a brown prothallus. The dark-brown to blackish, irregularly shaped apothecia are 0.2-1mm in diameter, not pruinose. Asci 8-spored, spores becoming brown with age, 4-6 septate, 26-36 x 10-13 Ám.
Microscope photograph below.
Chemical reactions negative.

A species of oceanic woodlands. Occurs on smooth-barked trees in old, undisturbed woodland, mainly in the north and west of Ireland.

Similar: A. ilicinella. Usually on Hazel, smaller discs 0.1-0.6mm diam

Arthonia ilicina

Microscope photograph
Arthonia ilicina, ascospore
Arthonia ilicina. January 2011

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