Flora of New Zealand Series

P. degelii D. Galloway et P. James, Lichenologist 15: 141 (1983).

Holotype: New Zealand. Nelson, Mt Haast, on Nothofagus solandri var. cliffortioides at treeline. 28 December, 1978. DJ. Galloway, in CHR 381020! Isotype in BM. Named in honour of Prof. Gunnar Degelius (Göteborg) for his researches into Collema in New Zealand.

Thallus orbicular to irregularly spreading, 5-20(-30) cm diam., loosely attached. Lobes numerous, rounded to elongate-laciniate, very variable, 1-1.5(-2.5) cm wide and 2-3(-5) cm long, margins entire, ± sinuous or slightly notched, not phyllidiate, often subascendent, with punctate, yellow pseudocyphellae, sometimes ± canaliculate, rarely plane. Upper surface bright lettuce green, glaucous-green or pale yellowish-green when wet, pale yellowish-grey when dry becoming ochre-brown on storage, undulate or shallowly reticulate-faveolate, interconnecting ridges low, rounded, smooth, matt or shining, sometimes ± areolate-scabrid at or near lobe apices, minutely maculate (×10 lens). Medulla yellow. Photobiont green. Lower surface irregularly wrinkled, pale yellowish to ochre-brown at margins, dark red-brown to blackened centrally, often glabrous to sparsely or patchily tomentose to margins, tomentum silky, pale grey or whitish to medium brown, often ± tufted or ragged. Pseudocyphellae scattered, inconspicuous, sparse to numerous, punctiform, 0.5-1.5 mm diam., low-conical, decorticate area yellow. Apothecia sparse, often absent from well-developed thalli, sessile to subpedicellate, laminal, rarely marginal, 3-5(-10) mm diam., disc not fully exposed until late in development, partly obscured at first by inflexed, scabrid-verrucose exciple, disc red-brown, finely rugose, shining, subconcave to plane, thalline exciple conspicuous, persistent, pale whitish to buff, translucent when wet, very coarsely verrucose-areolate-scabrid. Epithecium granular, pale yellowish-brown, 13-22 µm tall. Hymenium colourless, 80-110 µm tall. Hypothecium c. 100 µm thick, pale yellowish-brown. Paraphyses conglutinate, simple, filiform, 1.5 µm thick, apices swollen to 5 µm thick, yellow-brown. Asci clavate 70-90 × 10-22 µm. Ascospores biseriate, ellipsoid-fusiform, apices pointed, straight or slightly curved, colourless, 1-3septate, 3-septate at maturity, (20-)25-34(-39) × 6.8-8.3 µm. Chemistry: Pulvinic dilactone, pulvinic acid, calycin, stictane-3β,22αdiol (±), 22α-hydroxy3,4,secostict-4(23)-ene-oic acid, 22α,hydroxy-3,4-secostict-4(23)-en-3-ol (±), 3acetoxy-3,4-secostict-4(23)-en-22α-ol (±). See Goh et. al., (loc. cit.).

N: Gisborne (Urewera National Park), Wellington (Thunderbolt, Kaimanawa Ra.). S: Nelson to Fiordland, close to Main Divide, eastwards on foothill ranges of Canterbury and Otago, to Silver Peaks, Hightop and Maungatua near Dunedin and Forest Hill and Waihopai Scenic Reserve (near Invercargill). St: (Mt Anglem). C: (Mt Azimuth). Very rarely at s.l., mainly subalpine - alpine in Chionochloa grassland, often at the base of Dracophyllum or on bark and canopy branches of Nothofagus menziesii and N. solandri var. cliffortioides, especially at treeline, 500-2000 m.

Endemic

P. degelii appears to have two main growth forms, a corticolous form has thicker lobes which are often wrinkled or reticulate-ridged and sparsely fertile, and a grassland form has thinner, more papery lobes which are undulate, smooth and never or rarely reticulate-ridged and very rarely fertile. This latter form was called Sticta endochrysa in earlier accounts of New Zealand lichens, however true P. endochrysa, which is a South American species, does not occur in New Zealand. P. degelii is related to the South American P. berberina [Galloway and James Lichenologist 9: 95-105 (1977); Lichenologist 12: 293 (1980)] but differs in several respects. It is distinctive chemically [Wilkins Phytochemistry 16: 2031-2032 (1977), Goh et al., loc. cit. ]. The lobes are narrower and not as broadly rounded, margins are entire or notched but not conspicuously indented, incised or ± phyllidiate as in P. berberina. In P. degelii the upper surface is smoother, less deeply faveolate and more rarely areolate-scabrid, the thalline exciple is also much more massively developed (even at an early stage) and is much more coarsely verrucose-areolate-scabrid. Spores in P. degelii are consistently shorter and thicker than in P. berberina. Chemistry appears however to be the most persuasive distinguishing character and also sets P. degelii apart from the related P. flavicans though in this case the marginal and laminal phyllidia of P. flavicans are diagnostic.