• Placynthium tantaleum (Hepp) Hue
Placynthium tantaleum
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(Map updated: 11 August 2009)

This lichen is very easily mistaken for P. nigrum. The smaller thallus (to 3cm diam.) of minute pimple-like granules, the broadly ellipsoid spores (to 9m across compared with 6m in P. nigrum) and habitat of intermittently submerged rock such as by the edge of lakes, usually serves to distinguish it. In Ireland, the species is very rare and poorly known.

Key characteristics

  • Small thallus, dense with granules
  • Spores broader than in P. nigrum; habitat of lake margins and particularly tolerant of fluctuating submergence.

Original text submitted by Vince J. Giavarini

 Simms, M. J., (2016). Placynthium tantaleum (Hepp) Hue. [In] LichenIreland. Accessed on 2020-05-26.