Images of British Lichens
Opegrapha herbarum Mont.
Thallus thin, grey to olive or brown; fruitbodies lirellate apothecia up to 2mm in length, very variable, shortly elongated to longer, curved, sometimes branched, narrowly opening to expose the discs, which become fully exposed with maturity, sometimes green-pruinose, outer margin minutely red-brown, pycnidia rare. Part of a difficult genus commonly requiring microscopic examination of the spores for accurate identification, ascospores 3-septate, somewhat clavate or with an enlarged inner cell, (16-)18-24(-26) × (4-)5-7(-8) µm (dimensions from Pentecost & James, in Smith et al., 2009). Widespread, mainly on sheltered, smooth, bark but also recorded on bramble (Rubus) and dead herbaceous stems and rarely on sandstone..
Refs: Smith et al. (2009), 640; Purvis et al. (1992), 408; Dobson (2005), 290; Dobson (2011), 293; van Herk & Aptroot (2004, 2013), 270-1 (photo); Valcárcel et al. (2003), 258-9 (photo, as O. culmigena).
|On dry bark of Beech (Fagus sylvatica), Logie, Morayshire, August 2010 (BLS meeting)|
|On Hazel (Corylus avellana), Ardclach, Morayshire, August 2010 (BLS meeting)|
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uploaded February 2014