Steinera polymorpha P.James & Henssen
Holotype: New Zealand, Southland, Dusky Sound. In grassland, Cascade Cove, 1000 m. DJ. Galloway, 10.ii. 1967, BM!
Thallus ± placodioid, spreading, to 5 cm diam., rather loosely attached, ± polymorphic, margins lobate, terricolous or saxicolous. Marginal lobes radiating, ± distinct to 2 mm wide, contiguous, rarely imbricate, apices rounded sometimes notched, flabellate. Upper surface pale cream to bluish-grey, often coarsely scabrid, centrally strongly radially fissured, ± crustose, with numerous anastomosing coarse ridges and cracks, or ± irregularly areolate, areolae separated by coarse, gaping cracks. Apothecia to 0.9 mm diam., at maturity, at first urceolate, deeply immersed in thallus, gradually emergent, thalline margin at first inflexed, later hardly apparent or slightly raised above disc, discrete to 2-4-confluent, the combined disc sometimes dissected by fine to rather coarse cracks, disc dark red-brown, matt or shining, to slightly roughened. Ascospores elongate-fusiform with one or both ends ± tapering, (55-)65-75 × (4.5-)5-5.5(-6.5) µm, (5-)7-septate, locules equal in length. Pycnidia numerous, small, irregular dark spots on upper surface not easily distinguished from young apothecia without microscopic examination. In section large, ± rounded or vertically elongate, c. 800 × 600 µm, conidiophores repeatedly branching forming a network, conidia formed laterally, ellipsoid to ± rod-shaped, 4-5 × 1.5 µm.
S: Known only from the type collection.
Endemic
S. polymorpha is a species of rather variable morphology. The centre of the thallus is variously contorted and ± deeply fissured, however the margins are effigurate-lobate as in other species of the genus. It most closely resembles S. sorediata in spore morphology, but it lacks soredia and the apothecia remain ± immersed in the thallus whereas in S. sorediata apothecia are conspicuously emergent with a prominent, sorediate margin. The pycnidia are characteristic and appear similar to those found in Dermatocarpon weberi. The inner part of the pycnidium is ± filled with proliferating conidiogenous cells bearing conidia laterally. The pycnidia do not have convoluted walls, a characteristic feature of S. radiata. S. polymorpha occurs in Chionochloa grassland on an open rocky ridge above Cascade Cove, Dusky Sound, in damp hollows on stones and among moss often in association with Siphula fragilis and species of Placopsis.
