Epilithic thallus scarcely developed; I+ intensely violet. Apothecia numerous, black, epruinose, up to 1.1 mm in diam., with distinct thin margin and well constricted base. Hypothecium medium brown, marginally intruding into slightly reduced exciple. Excipular hyphae 3.0–4.0 µm wide, with apical cells 4.0–5.0 µm wide. Apical cells ofparaphyses: 3.0–3.7 µm wide. Hymenium 60–65–70 µm tall, subhymenium 25–30–40 mm tall. Ascospores scarcely developed, ellipsoid, 10.0–11.5–13.5 X 4.5–5.9–7.0 µm. Pycnospores bacilliform, 7.5–11.5–17 X ca 1.0 µm. TLC did not show stictic acid, but some unidentified substances (contamination?). We are not absolutely sure about the con specifity of Lecidea reducens and L. lapicida, but have no better idea of placement. Vainio (1909) placed Lecidea reducens near to Lecidea auriculata, however the latter taxon has much smaller ascospores.
Lecidea lapicida var. lapicida occurs in cool temperate and humid regions and is a very widespread and locally common taxon. Its world distribution was mapped by Hertel (1985) and the Arctic North American distribution by Thomson (1997). Recently it was recorded for St. Matthew Island (Bering Sea, Alaska) by Talbot et al. (2001). There are many earlier records of this species from the region, e.g., from Chukotka (Andreev 1984; Makarova 1983; Makarova & Katenin 1983, 1990; Nylander 1888; Vainio 1909), from Wrangel Island (Dobrysh 1995; Makarova 1981), from Arctic Yakutia and Novosibirskiye Islands (Egorova et al. 1991; Makarova et al. 1988), and from the Kolymskoye upland (Kotlov 1995).