Flora of New Zealand Series

≡Caloplaca acheila var. rubentior Zahlbr., Denkschr. Akad. Wiss. Wien math.-naturwiss. Kl. 104: 368 (1941)

Caloplaca acheila var. rubentior. Lectotype: New Zealand. Northland, Hen I., just above high tide, 17.xi.1933, L.M. Cranwell ZA 261 – CHR 374040 [fide Galloway (1985: 62)]. Isolectotype – UPS.

Description : Thallus of scattered, minute, orange granules, granules rounded to sublinear, 0.1–0.6 mm diam., aggregated around clumped apothecia, or absent. Apothecia prominent, sessile, rounded to contorted through mutual pressure, aggregated in clumps or lines, 0.2–1.2(–2) mm diam., disc subconcave to plane, matt, orange, rarely with small plugs of sterile tissue centrally; thalline margin not apparent, or present as a thin margin below disc, concolorous with thalline granules; proper margin prominent, persistent, swollen, glossy, concolorous with or paler than disc. Epithecium yellow, granular, 8–12(–17) μm thick. Hymenium colourless, without oil droplets, 55–65 μm tall. Paraphyses slender, 1–2 μm thick, apical cells submoniliform, to 5 μm thick. Asci cylindrical, 50–55 × 10–12 μm, 8-spored. Ascospores broadly ellipsoidal to ovoid, 11.5–15 × 8–10 μm; septum 5–6 μm thick, ⅓ to ½ length of spore.

Chemistry : Thallus and apothecia K+ reddish purple; containing parietin, emodin, fallacinal and fallacinol (Santesson 1970).

N: Northland, Auckland.

Endemic

Caloplaca rubentior is characterised by: the saxicolous (coastal rocks) habit; a thallus of scattered, minute, orange granules aggregated around clumped apothecia; prominent grouped apothecia, 0.2–1.2(–2) mm diam., the discs orange, matt, rarely with plugs of sterile tissue, and with a prominent, persistent, glossy proper margin, concolorous with disc or paler; a hymenium without oil droplets, 55–65 μm tall; cylindrical asci, 50–55 × 10–12 μm; and broadly ellipsoidal to ovoid ascospores, 11.5–15 × 8–10 μm; septum 5–6 μm thick, ⅓ to ½ length of spore.