Enterographa zonata and Opegrapha gyrocarpa New to North America

Abstract

Enterographa zonata and Opegrapha gyrocarpa are reported new to North America from Canada. During recent field work on corticolous crustose lichens in Nova Scotia on the Atlantic coast of Canada, the senior author happened to pick up a few specimens of the saxicolous lichens Enterographa zonata and Opegrapha gyrocarpa. These species were of particular interest as they were not listed by Egan (1987) or in the recent changes to his checklist (Egan 1989, 1990). However, Opegrapha gyrocarpa had already been identified by the junior author from material he collected in 1971 from the Queen Charlotte Islands on the Pacific coast. As we know of no previous North American records of Enterographa zonata and Opegrapha gyrocarpa, their occurrence on this continent is reported here. Enterographa zonata and Opegrapha gyrocarpa are widely distributed in Europe (e.g., Kopaczevskaja et al. 1977; Poelt 1969; Torrente & Egea 1989; Wirth 1987) where they inhabit continuously shaded, silicious rock underhangs in humid situations (James et al. 1977). ENTEROGRAPHA ZONATA (Koerber) Killsten Opegrapha zonata Koerber The species was found on a steep, shaded overhanging rock wall on the bank of a river. The specimens formed a mosaic comprising a number of individual thalli or were intermixed with colonies of Opegrapha gyrocarpa. The thalli were elongate, to 1(-2) cm in diameter, and were separated by a blackish border line. Apothecia, sparingly present in some specimens, were black, conical, and perithecia-like; the spores were fusiform, 5-septate, and 32-34 x 4-5 gm. The specimens contained confluentic acid and 2'-O-methylmicrophyllinic acid by TLC. Enterographa zonata is a distinctive species, even when sterile, on account of its brownish thallus with a more or less distinct lilac tinge and the punctiform soralia. The species has been recently treated for southwestern Europe and northern Africa by Torrente and Egea (1989). An excellent color photograph has been published by Wirth (1987). According to Wirth (1987), the species has its distributional optimum in western, northwestern, and central Europe. In Great Britain E. zonata is mainly western (Pentecost & Coppins 1983). In Norway it is restricted to coastal areas (Botnen & Tonsberg 1988). Apparently E. zonata is best classified as a suboceanic species. Specimens examined. -CANADA. NOVA SCOTIA. HALIFAX Co.: Musquodoboit Harbour, Musquodoboit River Gorge, W of Tom Vaughans Pool, UTM grid. ref.: 20T, ME 888595 (series A791, map 11 D/14), alt.: 0-5 m, Tonsberg 16828, 16829 (BG). OPEGRAPHA GYROCARPA Flot. In Nova Scotia this species was very abundant, covering extensive patches on a rock wall. It was closely associated with Enterographa zonata. On Queen Charlotte Islands the species was found at the base of a rock wall at the edge of a lake surrounded by a Thuja-Tsuga forest. Opegrapha gyrocarpa is a variable species. The specimens from Nova Scotia were sterile and had a brownish or yellowish-brown overall color and numerous, punctiform soralia with a yellow or pinkish tinge. Schizopeltic acid with satellites was found by TLC. The specimen from Queen Charlotte Islands was richly fertile, but otherwise it was morphologically similar to the specimens from Nova Scotia. The apothecia were black, rounded, and with a more or less gyrose disc; the spores were 3-septate, 20-25(-27) x 4-5 ,gm. Gyrophoric acid and a trace of lecanoric acid were demonstrated by TLC. In Norwegian material three chemotypes occur: 1) with schizopeltic acid as the major substance, 2) with gyrophoric acid as the major substance, and 3) with schizopeltic and gyrophoric acids as the major substances. Thus, two of the three chemotypes are represented in North America. In Europe O. gyrocarpa is common in the western, northwestern, and central parts (see, e.g., Wirth 0007-2745/92/225-226$0.35/0 This content downloaded from 157.55.39.107 on Wed, 30 Mar 2016 05:28:55 UTC All use subject to http://about.jstor.org/terms 226 THE BRYOLOGIST [VOL. 95 1987). In Norway it occurs most commonly along the coast but inhabits humid sites in the inland as well (Botnen & Tonsberg 1988), indicating that it is less dependent on an oceanic climate than Enterographa zonata. Opegrapha gyrocarpa is another item in a growing list of relatively rare, bicoastal, oceanic or suboceanic lichens. Other examples include Erioderma mollissimum (Samp.) Du Rietz (see Ahti & Jorgensen 1971; Jorgensen 1972; Maass 1983; Noble et al. 1987) and Cavernularia hultenii Degel. (Ahti & Henssen 1965), as well as the more common Platismatia norvegica (Lynge) Culb. & C. Culb. (Culberson & Culberson 1968) and Nephroma laevigatum Ach. (Wetmore 1960). Specimens examined.--CANADA. BRITISH COLUMBIA. QUEEN CHARLOTTE ISLANDS: Graham Island, Ian Lake, east end on south shore, 53047'N, 132003'W, Brodo 18412 (CANL, BG). NOVA SCOTIA. HALIFAX CO.: Musquodoboit Harbour, Musquodoboit River Gorge, W of Tom Vaughans Pool, UTM grid. ref.: 20T, ME 888595 (series A791, map 11 D/14), alt.: 0-5 m, Tonsberg 16830 (CANL; with Enterographa zonata), 16831 (BG; with E. zonata).