Catapyrenium daedaleum
≡Endocarpon daedalum Kremp., Flora 38: 66 (1855).
Description : Thallus squamose. Squamae 1–4 mm diam., adnate or with slightly raised margins, irregularly rounded, dispersed or confluent to subimbricate; outer squamae enlarged, making thalli ±orbicular. Upper surface brown, with a green-grey tinge, dull, ±scabrid, matt or slightly pruinose. Lower surface dark, felted. Thallus 200–400 μm thick, upper cortex 10–30 μm thick, of small, rounded-angular cells 5–8 μm diam. Photobiont cells 5–12 μm diam. Medullary tissue ±cellular. Lower cortex absent, the medulary hyphae gradually merging into a dark, spongy hypothallus of densely interwoven rhizohyphae. Perithecia ±abundant, immersed, up to 300 μm diam., walls pale brownish, darker around ostioles. Periphyses 20–25 × 2–3 μm. Asci clavate, 75–85 × 17–20 μm. Ascospores biseriate, oblong-ovoid to drop-shaped or more rarely fusiform-ellipsoidal, 17–22 × 6–8 μm.
S: Growing over mosses and humus, especially over calcareous soils (Thomson 1989). Known also from Europe, Scandinavia, the Arctic, North and South America (Breuss 1990a, 1993a, 1995; Thomson 1989; Goward et al. 1994b; Esslinger & Egan 1995; Nimis & Martellos 2003), Siberia, Turkey, Mongolia, China, Taiwan, Nepal, the South Orkney Is and the South Shetland Is (Breuss 1998a; Aptroot 2003a; Søchting et al. 2004).
Bipolar
Illustrations : Thomson (1989: 191, fig. 1); Goward et al. (1994b: 35, fig. 4B); Hansen (1995: 87).
Catapyrenium daedaleum resembles C. cinereum and is often mistaken for that species. However, it has more rounded and thicker and less pruinose squamae than C. cinereum, and importantly, it lacks a lower cortex.
