Parabagliettoa dufourii
Thallus immersed, the surface usually level with surrounding rock or slightly lower, pale grey to brown-grey, not cracked; sometimes thallus units reaching to surface of rock as minute, brown specks. Prothallus not seen, but the leading edge of thallus sometimes white, and the junction with neighbouring, conspecific thalli marked by a fine crack, groove, change in level, a whitish (rarely brown) line, or a row or double row of brown pycnidia. Description adapted from Orange et al. (2009). Map © BLS. |
Assessed by Woods & Coppins (2012) as of Least Concern. It has a scattered but broad distribution.
Distinguished by the immersed thallus, often dotted with pycnidia, the perithecia which typically have a concave apex and the usually somewhat oblong ascospores. Perhaps previously over-recorded for Verrucaria pinguicula which is very similar, but with the thallus usually at least thinly superficial and often cracked, the perithecia less obviously depressed above and without pycnidia. V. pinguicula is probably a more northern species than P. dufourii.
Widespread in limestone areas of the British Isles. BLS map here.
On hard limestones.