Flora of New Zealand Series

P. montagnei (Church. Bab.) D. Galloway et P. James, Lichenologist 12: 300 (1980).

Sticta montagnei Church. Bab., Fl. N.Z. 2: 284 (1855).

Lectotype [fide Galloway and James loc. cit., p. 300 (1980)]: New Zealand. Sine loco. A Sinclair, BM!

Thallus ± orbicular, closely attached in rosettes or spreading, to 12 cm diam. Lobes rounded, ± radiating, imbricate, margins entire or delicately notched or incised, sinuous or ragged-phyllidiate. Upper surface glaucous-green to olivaceous when wet, pale greyish-green when dry, undulate or shallowly faveolate, lacunose, ridges smooth, matt or shining, without soredia, maculae or pseudocyphellae, often phyllidiate. Phyllidia dentate-subcoralloid, flattened, undulate, squamiform, marginal and laminal. Photobiont green. Medulla white. Lower surface pale yellowish-buff to whitish, slightly darker centrally, ± glabrous or with a sparse, thin, pale tomentum, wrinkled-bullate in parts, or ± papillate. Pseudocyphellae inconspicuous, very sparse, scattered, minute, erupting on ridges and papillae, decorticate area yellowish, or white. Apothecia laminal or marginal, sparse to moderately frequent, sessile to subpedicellate, 2-5 mm diam., disc matt, smooth, black, epruinose, margins thin, entire to crenate-striate to phyllidiate, pale. Pycnidia frequent, scattered, black, punctiform, minute. Ascospores brown, polaribilocular, fusiform-ellipsoid, 24-31 × (5-)7-10 µm. Chemistry: Hopane-6α,7β,22-triol, methyl evernate, methyl lecanorate, methyl gyrophorate, tenuiorin, gyrophoric, stictic, constictic and norstictic acids.

N: North Auckland (Three Kings Is southwards) to Wellington. S: Westland (Greymouth). Primarily a northern, coastal species from trees and shrubs in forest in moderate shade to full sunlight. Leptospermum and Cordyline are common phorophytes.

Endemic

P. montagnei is related to P. hookeri but has a green photobiont and is a more closely appressed bark species. It is distinguished from P. durietzii by the marginal and laminal phyllidia and the phyllidiate apothecial margins and in the morphology of the lower surface and pseudocyphellae. Some confusion has arisen over the correct taxonomic circumscription of this lichen since the pseudocyphellae on the lower surface are small, rather poorly developed and sparsely scattered. Very often also the lower surface lacks any conspicuous tomentum - the reason for its earlier designation as either Lobaria or Ricasolia.

Babington ( loc. cit., p. 284) wrote of P. montagnei"... The apothecia are those of a Sticta bursting from under the gonimic stratum, and remarkable for their crown-bearing leafy margin, which is singularly inflexed, so as often to conceal the disc in great measure. Sporidia minute, contained in elongated asci, subfusiform, not very regular in form, brown, not containing septa as far as I could observe. The thallus also sometimes has manifest traces of cyphellae, but other specimens would lead anyone to consider them a Parmelia as Dr Montagne was disposed to do, to whom I dedicate the plant, which seems to be undescribed...".