Flora of New Zealand Series

R. insularis (Nyl.) Rambold & Hertel, in H. Hertel, Lecideaceae Exs. Fasc. 8: 9, No. 159 (1985).

≡*Lecidea insularis Nyl., Bot. Not. : 177 (1852).

Description : Lichenicolous. Thallus medium to dark glossy brown, ±bullate-areolate, forming small islands, 3–30 mm diam. on the thallus of its host, Lecanora rupicola. Apothecia numerous, black, to 0.9 mm diam, sessile, not constricted at base, between areolae and often overtopped by them; disc flat, margins thin. Exciple to 40 μm wide, brown-black. Hymenium 45–70 μm tall, colourless. Epithecium greyish olive. Hypothecium brown-black with a ±unpigmented subhymenial layer, 35–50 μm thick. Ascospores ellipsoidal, 8–10(–15) × 4.5–6.5 μm.

Chemistry : Thallus K−, C− or + red, Pd−; containing ±gyrophoric acid.

S: Canterbury (Devil's Gap, Banks Peninsula), Otago (Poolburn, Teviot River, Old Man Ra., Little Valley Rd, Gem Lake Umbrella Mts). Parasitic on Lecanora rupicola : on both basaltic and schist rocks, lowland to high-alpine (460–1540 m), in exposed sites and in underhangs. It is widespread in Great Britain, Europe and Scandinavia reaching as far north as Svalbard, and is known also from Canada (Alberta, Saskatchewan, Newfoundland), the western United States (Alaska to Arizona), Macaronesia (Madeira, Tenerife), Chile and Australia (Hertel 1985b, 1987b, 2001a; Rambold 1989; Hertel & Rambold 1990; Elvebakk & Hertel 1997; Fryday 1999; Scholz 2000; Coppins 2002b; Hawksworth 2003; McCarthy 2003c, 2006; Nimis & Martellos 2003; Sérusiaux et al. 2003; Kainz & Rambold 2004b).

Bipolar

Exsiccati : Hertel (1985a: No. 159).

Illustrations : Wirth (1995b: 822); Lumbsch (1997b: 9, fig. 1F; 22, fig. 9F; 23, fig. 10A, B; 42, fig. 23F; 43, fig. 24D; 53, fig. 32D); Lumbsch et al. (2001: 29); de los Ríos et al. (2002: 947, figs 1–6; 949, figs 7–12; 951, figs 13–18).

* Rimularia insularis is a lichenicolous lichen, capturing algae from its host (de los Ríos et al. 2002), characterised by: the glossy, dark-brown, areolate thallus; and the parasitic habit on Lecanora rupicola. It is not found on Lecanora farinacea, which is so common in New Zealand, but is known elsewhere as a parasite on Lecanora subplanata Nyl. and Lecanora sulphurata (Nyl.) Zahlbr. (Hertel 1985b). Recently, Sérusiaux et al. (2003: 27) recorded this species as an autonomous lichen (from rocks in the Ardennes), not associated in any way with Lecanora rupicola.