Flora of New Zealand Series

≡Physcia elegans var. biatorina A.Massal., Flora 35: 565 (1852).

Description : Thallus in closely attached, spreading rosettes, 1–2(–4) cm diam. Lobes convex, plicate-radiate, narrow (0.1–0.2 mm diam.), closely contiguous at margins to deeply areolate centrally, orange-yellow, smooth to minutely papillate (×10 lens), never pruinose, sometimes abraded and exposing white, basal prothallus. Apothecia crowded centrally, sessile, rounded to angular-contorted through mutual pressure, 0.1–0.3(–0.5) mm diam., disc matt, plane or subconcave, dark orange-red or orange-brown; thalline margin concolorous with thallus, markedly paler than disc, prominent, persistent, swollen, entire, obscuring disc at first; proper margin not apparent. Epithecium granular, yellow-brown, 8–10 μm thick. Hymenium 65–75(–80) μm tall, without oil droplets. Paraphyses slender 1.5–2 μm thick, apices submoniliform, swollen to 5 μm diam., occasionally branched. Asci cylindrical, 50–60 × 10–13.5 μm, 8-spored. Ascospores oval-ellipsoidal apices rounded or pointed, 11.5–13(–15) × 5–7 μm; septum 3–5 μm thick, ¼ to ⅓ length of spore.

Chemistry : Thallus K+ purple; containing emodin, parietin, fallacinol, fallacinal, xanthorin and erythroglaucin (Santesson (1970: 2151).

S: Nelson (Cobb Lake), Otago (Dunstan Mts, Old Man Ra., Poolburn Reservoir, Rock & Pillar Ra.). On shaded, overhanging or vertical surfaces of schist tors in sheltered, S-facing sites where it associates with C. erecta and Lecanora cavicola and Protoparmelia badia. It is still very poorly known in New Zealand. Known also from Scandinavia (where it is rare), Europe, the Mediterranean, North Africa, Turkey and Asia (Nordin 1972; Nimis 1993; Santesson 1993; Poelt & Hinteregger 1993; Egea 1996; Seaward 1996; John 1996; Kondratyuk et al. 1996a, 1998; Thor & Arvidsson 1999; Scholz 2000; Diederich & Sérusiaux 2000; Hafellner & Türk 2001; Llimona & Hladun 2001; Nimis & Martellos 2003; Santesson et al. 2004).

Bipolar

Illustrations : Jahns (1980: 239, pl. 594); Wirth (1995a: 201, fig. 29F); Thor & Arvidsson (1999: 240).

Caloplaca biatorina is characterised by: the saxicolous habit; the neat, closely attached thallus rosettes; narrow, closely contiguous, convex, plicate-radiate lobes that become deeply areolate centrally; clustered, central small apothecia; 8-spored asci; oval ellipsoidal ascospores, 11.5–13(–15) × 5–7 μm; septum 3–5 μm thick, ¼ to ⅓ length of spore. Some collections have their apothecial discs abundantly parasitised by a species of Polycoccum.