Lecidea herteliana (All Fungi)
Thallus effuse, rarely more than 1–2 mm across; areolate, areoles flat to slightly convex, irregular, 200–400 µm across, grey to pale brown, often with a paler margin, contiguous or somewhat dispersed on a black hypothallus. Cortex 10–20 µm thick with pale brown (rarely red-brown or ± hyaline) pigmented upper layer 7–10 µm thick; epinecral layer thick, 45–95 µm, 20–25 µm at edge of areoles; medulla and upper cortex I+ blue. Photobiont chlorococcoid, algal cells 9–15 µm diam.
Anamorph: not known.
Teleomorph: ascomata apothecia, 400–600 µm diam, black, lecideine, sessile, slightly convex with a thin (ca 50 µm), barely raised margin. Excipulum dark blue-black with swollen (to 5 µm diam) cortical cells. Hymenium 90–105 µm tall; epihymenium ca 10 µm tall, sharply delimited, blue-black (H+ blue, N+ red; cinereorufa-green). Hypothecium dark brown. Interascal tissue: paraphyses sparingly branched and anastomosing, ca 1.5–2 µm diam, swelling at the apex to ca 5 µm with a dark blue-black cap. Asci 45–50 x 12–15 mm, cylindrical to slightly clavate, Lecidea–type. Ascospores 12–14 x 5–6 mm, simple, hyaline.
Chemistry: all spot tests negative; no substances detected by TLC.
Lecidea herteliana has a small (usually <2 cm diam), pale grey-brown, atrobrunnea-type thallus with an I+ blue medulla but all other spot tests are negative. It most closely resembles L. paupercula but that species has a more wide-spreading, red-brown to dark grey-brown thallus that contains stictic acid (K+ yellow, Pd+ orange). L. paupercula also differs in having flat to slightly concave areoles with a dark margin, red-brown pigmented cortical cells and a much thinner epinecral layer (20–35 mm), as well as flat ± innate apothecia.
In GB&I, known from several sites in the Scottish Highlands (Isle of Mull, Rannoch, Strontian, East Perthshire, Angus). Also present in NE North America (Maine).
On basalt and various other unspecified rocks and boulders.