Irish lichens

Opegrapha vulgata

Order: Arthoniales       Family: Opegraphaceae

Species: Opegrapha vulgata

Growth type crustose.
Photos: Co. Cork, Ireland.

Very variable. Thallus thin, smooth or +/- cracked, white, grey or brownish, often olive-tinged. Slender lirellae to 2.5 mm long, curved, straight, stellate or forming interlocking networks, the discs usually remaining slit-like. Asci 8-spored, spores (15-)20-30(-40) x 2.5-4(-4.5) µm, 4-7 septate. Pycnidia often present, conidia sickle-shaped 9-18 x 1-1.5 or bacilliform 3-5 x 1 µm. Micrographs below.

Common throughout Ireland on shaded, smooth-barked trees and on smooth areas of rough-barked trees. Chemical reactions negative.

Similar: O. niveotra has shorter discs (to 1mm), worm-like conidia


Opegrapha vulgata

Opegrapha vulgata

Opegrapha vulgata

Micrographs
Opegrapha vulgata

Opegrapha vulgata
Opegrapha vulgata March 2010 and April 2012

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