Flora of New Zealand Series

Holotype: New Zealand. South Auckland, Lake Rotowhero (Green Lake), near Rainbow Mountain, 1500 m, on bark of Pittosporum tenuifolium, 21.vii.1983, D.J. Galloway – BM. Isotype – CHR.

Description : Thallus foliose, lobate, ±orbicular to irregularly spreading, 1–3(–4) cm diam., rather loosely attached. Lobes to 6 mm wide, discrete to subimbricate. Margins slightly thickened, sinuous, subascendent, entire, delicately incised or crenulate, sorediate. Soralia marginal, often ±sinuous, linear to limbiform, occasionally round, and spreading onto upper (or lower) surface; soredia coarsely granular, bluish. Upper surface ±uniformly arachnoid–tomentose, dark blue-green when wet, pale greyish or olivaceous-grey when dry, often with pale, brown-pink apothecial initials. Lower surface white, ecorticate, arachnoid, especially at margins, pale-buff towards centre, rhizinate; rhizohyphae white, buff to bluish, rarely blackened, in fascicles tufted at apices, in scattered groups or ±densely developed. Apothecia not seen. Pycnidia rare.

Chemistry : TLC−, all reactions negative.

N: Northland (Three Kings Is, Radar Bush, Te Huka, Waipoua State Forest, Poor Knights Is, Carpenter Bay, Tapu Bush N. Kaipara, Tutukaka, Little Barrier I.), Auckland (Waitakere Ra.), South Auckland (Cuvier I., Ngamotukarara I., Shoe I., near Te Awamutu, Te Kauri Reserve near Otorohanga, Snake Gully near Taupo), Wellington (Kapiti I.). S: Nelson (Granity to Westport), Westland (Bruce Bay), Marlborough (Blue Duck Scientific Reserve Seaward Valley). A species of damp, humid habitats (often among bryophytes) found on a range of phorophytes including Alsophila, Avicennia, Coprosma, Dacrydium, Dicksonia, Leptospermum, Nothofagus and also on cultivated Pinus and Salix species. It also occurs on pumice, clay banks and/or mossy rocks. Known also from India, Sri Lanka, Malaysia, Indonesia, Japan, the Philippines, Papua New Guinea, Australia, Tasmania, Hawai'i, Society Is, Tahiti, Western Samoa, Canada (British Columbia), United States (Oregon, Washington), Costa Rica, Ecuador, and Parque Nacional Torres del Paine in southern Chile (Galloway & Jørgensen 1987; Jørgensen & Galloway 1992b; Sipman 1993; Goward et al. 1994b, 1998; Jørgensen 1994c; Breuss & Brunnbauer 1997; McCune & Geiser 1997: 394; McCune et al. 1997; Elix & McCarthy 1998; Goward & Arsenault 2000; Jørgensen 2000d; Brodo et al. 2001; McCarthy 2003c, 2006; Geiser et al. 2004; Jørgensen & Arvidsson 2004).

Palaeotropical

Illustrations : Galloway & Jørgensen (1987: 391, fig. 29); Jørgensen & Galloway (1992b: 259, fig. 92B; Lumbsch & Kothe (1992: 280, fig. 3); Goward et al. (1994b: 65); McCune & Geiser (1997: 136); Jørgensen (2000d: 689, fig. 30); Brodo et al. (2001: 396, pl. 444).

Leioderma sorediatum is the sorediate counterpart of L. erythrocarpum. It is easily distinguished from other species in Leioderma by a combination of soralia and an arachnoid–hairy upper surface. It is often confused with Erioderma sorediatum, a species with which it is commonly sympatric; however, E. sorediatum is more narrow-lobed and has distinctive laminal arachnoid hairs and is PD+ orange (pannarin).