Flora of New Zealand Series

Lectotype: New Zealand. Wellington, Manawatu Gorge, on partly immersed rocks, H.H. Allan ZA 417 – CHR 373804 [fide Galloway (1985a: 68)].

Description : Thallus thin, minutely areolate, yellow or yellow-white, in irregular patches or lines amongst other crustose lichens, 2–10 mm diam. Apothecia scattered, solitary or 2–4-together, sessile, 0.2–0.6(–1) mm diam., disc clear-orange yellow, waxy, matt, plane to subconvex, proper margin thin, entire, persistent, whitish or pale-yellow. Epithecium pale-yellow, 5–8 μm thick. Hymenium colourless, without oil droplets, 45–55 μm tall. Paraphyses simple, septate to 2 μm thick, apices clavate, moniliform and occasionally furcate, to 4 μm diam. Asci broadly clavate to cylindrical, 45–48 × 10–13(–15) μm. Ascospores ovoid-ellipsoidal, apices rounded, (10–)11.5–13(–15) × 6.5–8.5 μm, septum 5 μm thick, ⅓ to ½ length of spore.

Chemistry : Thallus K−; apothecia K+ purple containing parietin.

N: Known only from the type collection. On partially submerged rocks, closely associated with Lobothallia radiosa and Lecanora pseudistera. Possibly more widespread in freshwater aquatic habitats.

Endemic

Caloplaca perileuca is characterised by: the saxicolous habit (partly immersed riverine rocks); the thin yellow to yellow-white thallus; scattered solitary to grouped apothecia, 0.2–0.6 mm diam., with a clear orange to yellow, waxy disc; the hymenium without oil droplets, 45–55 μm tall; broadly clavate to cylindrical asci, 45–48 × 10–13(–15) μm; and ovoid-ellipsoidal ascospores with rounded apices, (10–)11.5–13(–15) × 6.5–8.5 μm, septum 5 μm thick, ⅓ to ½ length of spore.