• Caloplaca lactea (A.Massal.) Zahlbr.
Caloplaca lactea
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(Map updated: 11 August 2009)

It is not uncommon in areas of hard, natural limestone to pick up fragments of rock only to find this species attached. C. lactea has a thin, almost invisible thallus defined by the extent and spread of the discs (to 0.5mm diam.) which are curiously distinctive: bright orange-yellow with a plump margin, especially when young. It is one of the first lichen calcicoles to colonise natural areas of dry, shattered, south-facing limestone. Local. Throughout Ireland.

Key characteristics

  • The habitat, absence of a brightly coloured thallus and neat, rounded, bright orange-yellow discs with a plump margin are useful pointers
  • Its poor competitive ability alongside mosses and more robust lichen calcicoles make it a good pioneer of dry, broken limestone fragments in built as well as natural environments.

Original text submitted by Vince J. Giavarini

 Simms, M. J., (2016). Caloplaca lactea (A.Massal.) Zahlbr.. [In] LichenIreland. Accessed on 2019-08-19.