Description:
Thallus forming cushions up to 3 cm in diam., composed of brown to dark-brown, partly ascending squamules with a paler margin, becoming blackened at the apices and at spots along the edges that become raised and evolve into isidioid structures 0.10.2 mm thick and 0.6 mm tall; squamules finally becoming completely blackened. Cortex composed of a single layer of thin-walled cells. Photobiont Nostoc, in short chains enclosed in a reticulum of hyphae, individual cells 5-6 m diam.
Apothecia fairly abundant but difficult to observe among the isidia, sessile, partly clustered, black, to 2 mm diam. with distinct proper exciple, to 200 m wide). Hymenium non-amyloid, 120-150 m high of simple, septate hyphae, apically with dark pigment. Asci to 150 m, slender, thin-walled, I+ blue, but without apical amyloid structures; ascospores hyaline, ellipsoid, 1719(20) 89 (10) m often with oil drops and occasionally appearing septate (pseudoseptae).
Conidiomata not observed.
Chemistry: No lichen substances (by tlc).

Distribution and Ecology: Known only from the summits of mountains on the Falkland Islands where it occurs among bryophytes on rock ledges.

Remarks: Although this species has the distinctive ascus structure of other species of Austrella its ITS sequence did not form a monophyletic clade with the type of the genus. However, support in this part of the phylogenetic tree for the Pannariaceae is low and it was considered preferable to describe it in Austrella rather than a widely-circumscribed, polyphyletic Psoroma.

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Thallus


Apothecia