Flora of New Zealand Series

≡Lecanora homologa Nyl., Bot. J. Linn. Soc. 9: 251 (1866).

≡Callopisma homologum (Nyl.) Müll.Arg., Bull. Herb. Boissier 2, App. 1: 51 (1894).

≡Triophthalmidium homologum (Nyl.) Gyeln., Acta Faun. Fl. Univ. ser. II, 1 (5–6): 8 (1933).

Lectotype: New Zealand. Otago "ad corticem arborem prope Dunedin", 1861, W.L. Lindsay – H-NYL 29605 [fide Hafellner & Poelt (1979: 26)]. Isolectotype – E.

Description : Flora (1985: 67).

N: Auckland, Hawke's Bay (Kumaroa), Taranaki (New Plymouth, Stratford), Wellington (Ruahine Ra., Manawatu Gorge, Wairarapa). S: Marlborough (d'Urville I.), Westland (Lake Kaniere), Canterbury (Hagley Park Christchurch, Kaituna Valley Banks Peninsula), Otago (Mt Trotter, Matanaka, Flagstaff, Leith Valley, Dunedin, Green Island, Saddle Hill), Southland (Invercargill, Tiwai Point, Cosy Nook). St: (Traill Park, Oban, Bird I., Muttonbird Is). On lowland, coastal trees and shrubs such as Coprosma crassifolia, Hebe elliptica, Hoheria, Myrsine chathamica, Plagianthus, Sophora, also on introduced trees in urban parks and street plantings in towns and cities, especially on Acer, Cupressus macrocarpa, Platanus, Populus, Quercus and Salix in sites of moderate to heavy pollution, and on fruit trees, e.g. Malus, and commonly associating with Haematomma babingtonii, Physcia adscendens, P. jackii, Ramalina celastri, Teloschistes chrysophthalmus, T. velifer, species of Usnea and Xanthoria parietina. Recorded also from the NW Himalaya (Awasthi 1991: 88).

? Palaeotropical

Illustrations : Knight (1880: pl. XIII, fig. 48); Hafellner & Poelt (1979: 5, fig. 10; 11, fig. 22).

Caloplaca homologa is characterised by: the corticolous habit; the dingy grey-white to olive-greenish, wrinkled, rosette-forming thallus; crowded ±central apothecia with red-brown to dark-brown apothecial discs and pale, crenulate, persistent thalline margins concolorous with the thallus; distinctive plurilocular (3–(5)-septate ascospores (Hafellner & Poelt 1979: 11, fig. 22). It is commonly (and understandably) mistaken for a species of Lecanora, until the ascospores are checked.