Flora of New Zealand Series

Holotype: New Zealand. South I., Canterbury: Hanmer Springs close to Information Centre, 26.xi.1980, L. Tibell9631 – UPS. Isotypes– BG, CHR 528305.

Description : Thallus subfoliose forming flat, smooth appressed rosettes on smooth bark, irregularly spreading on rough bark, to 1.5 cm diam. Lobes flat, discrete, to 1 mm wide and 200 μm thick, similar in structure to those in F. applanatum, enlarged apically and there with ascending margins. Upper surface bright malachite-green to blue-green when moist, fading to creamish buff when dry, except for delimited marginal isidioid blue-grey soralia. Prothallus poorly developed, of thin whitish rhizohyphae. Apothecia to 1 mm diam., sessile, flat, orange-brown with paler, distinct proper exciple. Hymenium colourless to 100 μm tall. Ascospores apiculate, ellipsoidal, 8–10 × 4.5 μm. Pycnidia not seen.

Chemistry : TLC−, all reactions negative.

N: South Auckland (Mt Pirongia). S: Canterbury (Hanmer State Forest), Otago (Rees Valley), Southland (West Dome). On bark of both introduced (Larix) and native trees (Nothofagus solandri var. cliffortioides), in moderate shade in habitats of high humidity, and among mosses on shaded rocks. Still rather poorly known and collected. Recorded once from Tierra del Fuego (Jørgensen 1999a).

Austral

Illustration : Jørgensen (1999a: 259, fig. 1).

Fuscoderma pyxinoides is a characteristic species that has a superficial resemblance to a species of Pyxine (its appressed , somewhat elongated lobes with marginal, delimited soralia). In this it differs markedly from other species of Fuscoderma, but it shares the very characteristic apothecia with the cyanobiont penetrating into the lower parts of the subhymenium (Jørgensen & Galloway 1989: 297), and lacking any amyloid structures in the ascus apex. In the material examined the apothecia are rare and sporadic and the species is more commonly encountered sterile. It is often found on mountain beech at the margins of forest where it can form quite dense, spreading colonies on old, furrowed trunks. The colour of the thallus closely resembles that of the bark, rendering the lichen often difficult to detect.