Physcia adscendens (Fr.) H.Olivier
Parmelia stellaris var. adscendens Fr., Summ. veg. Scand.: 105 (1845).
Thallus orbicular or confluent with other thalli, ± loosely attached, to 5 cm diam., corticolous, rarely saxicolous. Lobes variable, sometimes long and narrow, sometimes shorter and broader with long, terete, concolorous marginal cilia. Upper surface smooth, matt, greyish-blue to greenish-white. Soralia helmet-shaped, usually expanding on the underside forming rounded elevations visible from the upper side, soredia coarse, granular, white or greenish-white. Lower surface white to pale brown with sparse, blackened rhizines. Apothecia (not seen in New Zealand material) to 2 mm diam., disc often white-pruinose. Ascospores 16-23 × 7-10 µm. Pycnidia immersed. Conidia 4-6 × 1 µm. Chemistry: Cortex and medulla K+ yellow. Atranorin.
N: S: St: Widespread on bark, on introduced trees (shrubs and fruit trees in urban areas), and on divaricating shrubs in humid areas on disturbed sites such as river banks or roadside verges, coastal and inland, s.l. to 500 m.
Cosmopolitan
P. adscendens is a common epiphyte on eutrophic bark of introduced deciduous trees (especially Fraxinus).
