Lecanora melacarpella
=Lecanora haywardiorum Lumbsch in H.T. Lumbsch & G.B. Feige, Mycotaxon 45: 476 (1992).
Description : Thallus crustose, uniform, whitish to yellowish white or greyish white, continuous or dispersed verrucose to verruculose, epruinose. Margins indefinite or definite, sometimes with a whitish prothallus. Apothecia sessile, constricted at base, 0.6–1.8 mm diam.; discs very dark brown to brown-black, epruinose; margins smooth to verruculose or verrucose, prominent. Amphithecium with large crystals, but also small K-soluble crystals abundant. Parathecium hyaline with small, K-soluble crystals, bright whitish in polarised light, to 10 μm thick. Epithecium glabrata -type (Brodo 1984a), without crystals, with a 2-μm-high hyaline layer above; dark in polarised light, pigmented dark-brown to brown. Cortex 25 μm thick. Hymenium hyaline, 65–85 μm tall. Hypothecium hyaline. Paraphyses septate, c. 1.5–2 μm thick, only slightly swollen at apices. Asci clavate, 50–70 × 10–18 μm. Ascospores ellipsoidal, (9–)10.5–13.5(–15.5) × (5.5–)7.5–8.5(–9.5) μm.
Chemistry : Thallus and apothecial margins K+ yellow, C−, KC−, Pd+ yellow-orange; containing atranorin (major), zeorin (major), unidentified triterpenoid (minor) and chloroatranorin (minor).
N: Northland (Bay of Islands, Ririwha I., Poor Knights Is, Hen & Chickens Is, Great Barrier I., Little Barrier I.), South Auckland (Coromandel Peninsula, Rabbit I., Penguin I.). On coastal rocks. Also known from New South Wales and Queensland (Lumbsch & Feige 1992: 478–479; Lumbsch 1994: 114–115; McCarthy 2003c, 2006; Lumbsch & Elix 2004).
Australasian
Illustrations : Lumbsch & Feige (1992: 477, figs 1–6); Lumbsch (1994: 111, fig. 62D,E).
Lecanora melacarpella is characterised by: the saxicolous habit (coastal rocks); the dark-brown apothecial discs, the large and small crystals in the amphithecium, the L. glabrata -type epithecium. Superficially it resembles Tephromela atra but differs in having a hyaline hymenium, a different ascus type, and a differing chemistry.
