Flora of New Zealand Series

Sticta homoeophylla Nyl., Flora 50: 439 (1867).

Lectotype [fide Galloway and James loc. cit., p. 299 (1980)]: New Zealand. Sine loco (prob. Wellington). Charles Knight, BM!

Fig. 1

Thallus orbicular to spreading, often in dense swards, 10-20(-40) cm diam., loosely attached. Lobes broad, 1-3 cm wide, linear-elongate, dior trichotomously branching, to 12 cm long, apices discrete, contiguous to imbricate centrally, margins entire, sinuous, apices rounded or shallowly notched, without isidia, soredia, sinuses semicircular. Upper surface coriaceous, greenish or olivaceous when wet, yellowish-green to pale yellowish-grey when dry, smooth, shallowly wrinkled, undulate, matt or shining, without isidia, soredia, maculae or pseudocyphellae. Medulla white. Photobiont green. Lower surface pale buff or whitish at margins, dark brown, or black centrally, ± evenly tomentose, glabrous-wrinkled at lobe apices, tomentum short, dense, brown. Pseudocyphellae white, conspicuous, numerous, scattered, often crowded, to 1 mm diam. Apothecia emergent, submarginal or marginal, sparse to moderately common, 4-6 mm diam., subpedicellate, disc red-brown, epruinose, concave to plane, margins crenulate, pale whitish, thalline exciple corrugate-scabrid. Ascospores colourless to pale brownish, fusiform, 1-3-septate, 24-32 × 5-9 µm. Chemistry: 7β-acetoxyhopane-22-ol, hopane-15α,22-diol, hopane-7β,22-diol, norstictic, constictic and stictic acids.

N: South Auckland (Te Aroha and Pirongia) to Wellington. S: Nelson to Fiordland, mainly close to Main Divide in beech forest where often extensive areas of the forest floor are carpeted with this exuberant lichen.

Endemic

P. homoeophylla is characterised by the often broad, linear-laciniate lobes, entire margins, smooth, glabrous upper surface, green photobiont, white, conspicuous pseudocyphellae set in a thick, brown- black tomentum. It is the fertile counterpart species of P. delisea, however it is known only from New Zealand. P. delisea on the other hand, the presumptive derived species of P. homoeophylla, is widely distributed in south eastern Australia, the Subantarctic Islands and southern South America. P. homoeophylla often reaches a very great size and in Nothofagus forests of South I., literally covers the ground in dense swards. Both upper and lower surfaces of this lichen are shown in Martin and Child ( loc. cit., p. 131, pl. 37).