Verrucariaceae Staurothele caesia Growth type crustose. BLS conservation evaluation: LC NS Chemical results negative Local distribution on hard, unshaded limestone, rare on mortar Pale grey to brownish-grey endolithic thallus, the adjacent thalli sometimes separated by dark lines. Perithecia are immersed in deep pits, involucrellum absent. Asci 8-spored, spores muriform, 35-45 x 20-25 µm, colourless but pale brown when over-mature. Hymenial algal cells 3-5 x 3-3.5 µm. Similar: Staurothele guestphalica, rare, asci 2-spored

Staurothele caesia
On limestone. Portland, Dorset. March 2016