Peltigera nana
≡P. dolichorhiza var. nana (Vain.) Js. Murray, Trans. Roy. Soc. N.Z. 88: 394 (1960).
Description : Thallus rather large, orbicular to spreading 5–10(–15) cm diam. Lobes broadly rounded, 1–2(–2.5) cm wide, 2–6(–8) cm long, papery, much thinner in texture (100–200 μm thick) than P. dolichorhiza and P. polydactylon. Margins wavy–undulate, here and there ±inrolled, entire to minutely scalloped, occasionally with small, fuzzy-brown tomentose apothecial initials. Upper surface glabrous, dark blue-black when wet, pale-greyish or olivaceous to dark-brown when dry, matt, somewhat coriaceous, papery, smooth to undulate–crumpled, ±bullate or longitudinally ridged. Lower surface tomentose, pale. Veins flattened, diffuse, rather broad, 0.5–2.5 mm wide, ±coalescing and continuous at margins, anastomosing towards centre, pale-buff to reddish brown, smooth; interstices white, fibrous, oval to elongate. Rhizines discrete, widely scattered, slender, simple to fasciculate, pale-buff to dark-brown or black, 3–8(–12) mm long. Apothecia rather small, ±erect, occasional to rare, 3–5 mm diam., saddle-shaped, ±strongly inrolled, on marginal lobules; disc red-brown to dark-brown, matt, epruinose, margins pale-buff or pinkish, verrucose–roughened, ±obscured by disc. Ascospores straight or curved, acicular, colourless 5–7-septate, (40–)45–55(–60) × 2.5–4 μm.
Chemistry : Tenuiorin, dolichorrhizin, peltidactylin and zeorin (tr.).
N: Northland (Three Kings Is, Little Barrier I.), South Auckland (Maungatawhiri Coromandel Peninsula, Tokoroa), Wellington (Tararua Ra.). S: Marlborough (Anakiwa), Westland (Greymouth), Otago (Waitati, Birch I. Clutha River, Kaka Point), Southland (Argyle Burn near Waikaia) [map in Galloway (2000d: 24, fig. 9)]. In moist, though fairly open, ±disturbed habitats, on rocks, rotting logs, tree bases, on soil, among mosses and grasses at forest margins, or on roadside banks, where it often occurs with other species of Peltigera and with other lichens such as Cladia aggregata and Stereocaulon ramulosum. Known also from the Philippines (Murray 1960c).
Palaeotropical
Exsiccati : Vězda (1997e: no. 306).
Illustrations : Malcolm & Galloway (1997: 178, fig. 270).
Peltigera nana is characterised by: the muscicolous/terricolous/corticolous habit; broadly rounded, thin, papery lobes [about half the thallus thickness of P. dolichorhiza (P. nana is 100–200 μm thick, while P. dolichorhiza is 220–400 μm thick)], a glabrous upper surface, a pale lower surface with broad, flat, diffuse pale-buff to reddish brown veins, and discrete, scattered pale to dark, simple to fasciculate rhizines [3–8(–12) mm long], and a medullary chemistry of tenuiorin and three tripterpenoids.
