Flora of New Zealand Series

≡Peltidea hymenina Ach., Methodus: 284 (1803).

Description : Thallus rosette-forming to irregularly spreading, 3–8(–14) cm diam. Lobes linear, imbricate, 0.5–1.2(–2) cm diam., 2–6 cm long, rather thin, 200–300 μm thick. Margins entire or shallowly notched, wavy, ±inrolled in parts. Upper surface slatey blue-grey to brown-grey, suffused red-brown at apices when wet, olive-green to brownish green to pale-grey when dry, matt, minutely maculate (×10 lens, best seen when wet), without isidia, phyllidia or soredia. Lower surface without veins, or veins when present, flat, broad, indistinct, ±evenly felted-tomentose from centre to margins, or occasionally with small, scattered, whitish interstitial areas apparent at margins between veins (×10 lens), pale yellowish buff in a broad, marginal zone darkening centrally. Rhizines thin, scattered, simple to fasciculate, pale yellow-buff to dark-brown, generally rather short, 2–4 mm long. Apothecia rather rare, 3–5 mm long, saddle-shaped, on short marginal stalks, disc red-brown, epruinose, margins corrugate–roughened, pale-buff, tomentose below. Ascospores fusiform, 3–5-septate, 50–70(–80) × 3–4 μm.

Chemistry : Tenuiorin, methyl gyrophorate, gyrophoric acid, peltidactylin, dolichorrhizin, zeorin (tr.), hopane-7β,22-diol, unidentified triterpenoid (tr.).

S: Otago (Lake Onslow, Dunedin, Pukerau), Southland (Homer, Argyle Burn). St: (Tin Ra.) [map in Galloway (2000d: 16, fig. 5)]. Among mosses and bryophytes often with other lichens (especially Cladia aggregata, C. sullivanii) in subalpine grassland, or on soil or rocks, s.l. to 160 m. Known from the Northern Hemisphere from North America, Western Europe, the British Isles, Macaronesia and Africa (Purvis et al. 1992; Vitikainen 1994b; Nimis & Martellos 2003), but not elsewhere in the Southern Hemisphere.

? Bipolar

Illustrations : Wirth (1987: 343 – as P. lactucifolia; 1995a: 685); Holtan-Hartwig (1993: 47, figs 52, 53 – as P. lactucifolia); Vitikainen (1994b: 48, fig. 90); Dobson (2000: 284 – as P. lactucifolia; 2005: 317).

Peltigera hymenina differs from other taxa in the P. polydactylon aggregate by its mainly pale buff-brown lower surface, with ±continuous felted tomentum and rather diffuse venation, the somewhat maculate and less shiny upper surface, and the thin, pale, simple to fasciculate short rhizines.