This page is due for revision. It has been shown that the British concept of L. campestris includes L. horiza, as understood by continental lichenologists. True L. campestris is is a less attractive lichen with smaller apothecia and a fimbriate margin to the thallus. This page presently covers both species; the photographs show L. horiza.
Typically in circular colonies, thallus whitish to pale grey, warted and areolate, soralia lacking in this subspecies; apothecia usually abundant, red- to dark brown. Widespread and generally common on concrete and calcareous rocks.
Refs: Smith et al. (2009), 441; Purvis et al. (1992), 300; Dobson (2005), 216 (photo); Dobson (2011), 221 (photo); Allen (2007), 33 (photo); Wirth (1995), 1: 458; Wirth et al. (2004), 210 (photo); Wirth, Hauck & Schulz (2013), 1: 585, 591 (photo); van Herk & Aptroot (2004, 2013), 202-203 (photo); Valcárcel et al. (2003), 208-9 (photo).
Lichenicolous fungi on L. campestris include Vouauxiella verrucosa.