Images of British Lichens
Placidium squamulosum (Ach.) Breuss
(= Catapyrenium squamulosum (Ach.) Breuss)
Thallus consisting of individual to grouped, yellow- to red- or dark-brown squamules, pale beneath, with colourless rhizoidal hyphae; surface developing black spots, i.e. pycnidia and perithecia, which are laminar as distinct from marginal and immersed in the thallus surface. Widespread but local, on calcareous soil, including dunes, soil caps on walls, and in rock crevices.
Refs: Smith et al. (2009), 710; Purvis et al. (1992), 165 (as Catapyrenium); Dobson (2005), 115 (photo, as Catapyrenium); Dobson (2011), 347 (photo); Whelan (2011), 132 (photo); van Herk & Aptroot (2004, 2013), 114-5 (photo, as Catapyrenium); Wirth (1995), 1: 255 (photo, as Catapyrenium); Wirth et al. (2004), 170 (photo, as Catapyrenium); Wirth, Hauck & Schulz (2013), 1: 331, 2: 888 (photo); Stenroos et al. (2011), 370 (photo); Hinds & Hinds (2007), 409 (photo).
|On open ground in dune turf over limestone, Stackpole, Pembrokeshire, May 2009 (arrowed), with Psora decipiens, the pale brown thalli with white margins.|
Lichens HOME PAGE | Index of Species | Conditions of Use and e-mail contact | References | Site Home Page
© A.J. Silverside
Uploaded January 2012, last updated December 2013