Flora of New Zealand Series

≡Lecanora vitellinula Nyl., Flora 46: 305 (1863).

Description : Thallus effuse, thin and poorly developed, often reduced to scattered yellow-brown granules or lacking, K+ reddish purple. Apothecia minute, crowded to scattered in lines or in small groups, 0.1–0.5 mm diam., plane to subconvex, rounded to contorted through mutual pressure, disc golden-yellow to dull-orange, matt; thalline margin not apparent; proper margin prominent, persistent, swollen, entire, obscuring disc at first, paler than disc. Epithecium granular, yellow, 8–12 μm thick. Hymenium colourless, without oil droplets, 50–60 μm tall. Paraphyses slender 1–2 μm thick, apices swollen 4–5 μm diam., not branched or moniliform. Asci broadly clavate, 45–50 × 15–20 μm. Ascopores, broadly ellipsoidal to ovoid, apices rounded to slightly pointed, 10–12(–13.2) × 5.5–7 μm; septum 5–6.5 μm thick, ½ length of spore.

Chemistry : Thallus and apothecia K+ reddish purple; containing parietin.

S: Marlborough (Goose Bay), Otago (Wilson's Bluff, E Matukituki Valley, Alexandra, Roxburgh, Teviot Valley, Woodhaugh Bridge Dunedin). On dry, dusty, sunny schist rocks and outcrops and on loose schist pebbles on ground, and on stonework of bridges and retaining walls. Associating with Acarospora spp, Candelariella vitellina, Xanthoparmelia. Known also from Europe, Scandinavia, Morocco, Israel, Turkey, Ukraine, North America and Australia (Nimis 1993; Santesson 1993; Esslinger & Egan 1995; Egea 1996; Galun & Mukhtar 1996; John 1996; Kondratyuk et al. 1996a, 1996b; Scholz 2000; Hafellner & Türk 2001; Llimona & Hladun 2001; McCarthy 2003c, 2006).

Cosmopolitan

Illustration : Foucard (1990: pl. 79).

Caloplaca vitellinula is characterised by: the evanescent, saxicolous thallus; scattered to crowded, minute, golden-yellow, Candelariella- like apothecia (K+ purple); broadly ellipsoidal to ovoid ascospores, 10–12(–13.2) × 5.5–7 μm with a thick septum, 5–6.5 μm thick. The species was originally described from Alnus bark, but subsequently it has been applied exclusively to saxicolous forms.