Flora of New Zealand Series

Lectotype: New Zealand. Otago, Matanaka on limestone [calcareous sandstone], J.S. Thomson T 1787 [ZA 680] – CHR 345883 [fide Galloway (1985a: 216)]. Isolectotype – OTA.

Description : Flora (1985: 215–216).

Chemistry : TLC−, all reactions negative.

N: Wellington. S: Canterbury (Cave Stream, Castle Hill, Weka Pass), Otago (Matanaka, Green Valley), Southland (Clifden). On limestone and calcareous sandstone, growing with species of Caloplaca, Lecanora crenulata and L. dispersa, Physcia nubila, Placynthium nigrum, species of Rinodina and Sarcogyne regularis.

Endemic

Lecanora fertilissima is characterised by: the saxicolous habit (basic substrata especially limestone); the thick, rosette-forming white or creamy white, hummocky thallus; the clustered, central, apothecia, 0.1–1.0(–1.5) mm diam., with brown discs, often pruinose and prominent thick, flexuose thalline exciple, not deeply crenate; ellipsoidal ascospores, 8–10.5 × 3.5–5 μm; and a negative chemistry. L. albescens differs from L. fertilissima in the slightly larger apothecia that are red-brown and rarely pruinose, and the thicker, more prominently plicate–radiate thallus. Lecanora fertilissima differs from L. crenulata [J.S. Thomson specimens (T 2335) from Matanaka were named L. crenulata (Zahlbruckner 1941: 339), but are in fact typical L. fertilissima] in the persistent, hummocky thallus; the smooth to slightly crenulate thalline margins; and the narrower ascospores.