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 Add this item to the list  Thallus ± orbicular
   
Page number:152 
Remarks (internal):Physcia phaea resembles P. aipolia and P. cascadensis, but is distinguished from P. aipolia by occasionally growing on a bark and having apothecia that lack soralia and the heavy pruina characteristic of P. aipolia. Physcia cascadensis, a rare and rock-dwelling rosette lichen, like P. phaea lacks soredia and has a K + yellow medulla but differs in its very pale gray cortex, absence of maculae, and pruinose apothecia. 
Description type:Non-original description 
Description:Physcia phaea (Tuck.) J.W. Thomson, Beih. Nova Hedwigia 7: 54. 1963 Fig 3
Thallus ± orbicular, or irregular, to 1.5-2.2 cm in diam., usually closely appressed to the substratum, steel-gray to dark gray, or brownish gray, white maculae present, rugose; pruina, soredia, isidia or lobules absent; lobes radiating, flat to slightly convex, 1-1.5 mm wide, typically crowded and overlapping, eciliate. Medulla white. Lower surface white to dark gray or brown, with white to black rhizines. Lower surface pale tan to brownish, with abundant or sparse pale to brown rhizines, 0.3-1mm long. Apothecia numerous, 0.5-1.5 mm diam., margins lecanorine, crenulated when young, perfectly round and somewhat raised; disc dark brown to black, rarely covered with a white pruina; ascospores brown, 1-septate, Physcia-type, 16-20 x 7-9 µm. Cortex K + yellow, C + slightly yellow, KC + slightly yellow, P -. Medulla K + yellow, C -, KC ± yellow, P -. Thallus contains atranorin and zeorin. Pycnidia numerous; conidia immersed, subcylindrical, 4-6 x 1 µm.
Physcia phaea occurs mainly on granitic (less commonly, calcareous) rocks, or mosses (mostly in open areas), also on basaltic or gneissic and nutrientenriched rocks. Previously known from Asia, Australasia, Europe, and North America. New to Turkey and the Middle East.
 
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