Peltigera polydactylon
≡Lichen polydactylon Neck., Meth. Musc.: 85 (1771).
Description : Thallus orbicular to irregularly spreading, 2–8(–15) cm diam. Lobes irregular, linear–laciniate, ±discrete at apices, overlapping centrally, 0.5–1.5 cm wide, 1.5–3(–4) cm long. Margins entire, wavy, slightly thickened below, ±ascendent, often lacerate–incised to ±phyllidiate, or here and there with small, fuzzy, brownish apothecial initials. Upper surface glabrous, dark leaden-grey to blue-black when wet, pale blue-grey to somewhat brownish when dry, minutely maculate close to margins (×10 lens), glossy to matt, undulate, wrinkled, dimpled or ±bullate in parts, often irregularly longitudinally or laterally cracked with small phyllidia occasionally regenerating from margins of cracks. Lower surface tomentose, pale or whitish at margins, to buff or dark-brown centrally. Veins rather flattened to raised, 0.5–1.5 mm diam., pale-buff to dark-brown at margins, brown-black to black centrally, confluent to ±continuous at margins, soon anastomosing, and with ±oval to rounded, pale or whitish interstices. Rhizines simple to fasciculate, pale-buff to dark-brown or blackened, in rows or with ±confluent bases near apices, more widely scattered centrally, rather short, 2–4 mm long. Apothecia erect, round to saddle-shaped, 2–5 mm diam., on ±involute marginal stalks; disc pale to dark red-brown, epruinose; margins thin, crenate, pale-buff. Ascospores colourless, 3–5-septate, acicular, (48–)50–60(–64) × 2.5–4 μm.
Chemistry : Peltidactylin, dolichorrhizin, zeorin.
N: Northland (Three Kings Is, Radar Bush, Kawerua, Whangarei, Great Barrier I.), Auckland (Northcote), South Auckland (Moehau Coromandel Peninsula, Te Aroha, Kaimai Ra., Hatepe), Gisborne (Aniwanawa), Hawke's Bay (Puketitiri), Wellington (Ruahine Ra., Akitio, Tararua Ra., Orongorongo Ra.). S: Nelson (Kaituna Gorge, Flora Saddle, Mole Tops, Pelorus Bridge, Maruia Springs), Westland (Kelly's Creek, Greymouth, Haast, Waiatoto), Marlborough (Anakiwa, Wairau Valley, Kaikoura), Canterbury (Bealey River, Craigieburn Ra., Hinewai Reserve Banks Peninsula, Sealey Lakes, Peel Forest, Huxley Gorge Lake Ohau), Otago (Aspiring Hut, Rees Valley, Hidden Falls Stream, Beans Burn, Dunstan Mts, Merton, Whare Flat, Taieri Mouth, Kaka Point, Blue Mts, Tautuku Bay), Southland (Milford Sound, McKinnon Pass, Doubtful Sound, Dusky Sound, Manapouri, Monowai, Waihopai Reserve Invercargill, Seaward Bush, Longwood Ra., Port Craig). St: (Mt Anglem, Glory Cove, Ocean Beach, Anchorage I. Port Pegasus, Wilson Bay). A: C: [map in Galloway (2000d: 30, fig. 12)]. In moderate shade to high-light habitats on soil, among mosses and litter and rotting logs on the forest floor; on rocks, roadside banks, subalpine bogs and scrub; s.l. to 1800 m. Widespread in the Northern Hemisphere, South America and Australia (Vitikainen 1994b, 2004a; McCarthy 2003c, 2006).
Cosmopolitan
Illustrations : Moberg & Holmåsen (1982: 176); Thomson (1984: 343); Phillips (1987: 176); Olech & Alstrup (1988: 177, fig. 5); Holtan-Hartwig (1993: 63, figs 76, 77); Goffinet & Hastings (1994: 38, fig. 68, 39, figs 69, 70); Goward et al. (1994b: 102, fig. 47A); Vitikainen (1994b: 69, fig. 111); Wirth (1995a: 677); Brodo et al. (2001: 518, pls 613, 614).
Peltigera polydactylon is characterised by: the muscicolous/terricolus/saxicolous habit; linear–elongate lobes with wavy, ascendent margins that are often phyllidiate; it has a glabrous, glossy upper surface; ±erect apothecia on involute stalks; simple to fasciculate, rather short rhizines which are often in rows or with ±confluent bases at the margins; and with hopane triterpenoids in the medulla. It is distinguished from P. dolichorhiza by the wavy, ascendent margins and the presence of marginal phyllidia, and the rather shorter rhizines.
