Parmelia saxatilis #

Taxon #

Parmelia saxatilis

Organization #

Shield-Like Parmelioids

Identification #

A gray shield lichen that can brown in sunny sites. Isidia and apothecia common in Alaska specimens and with the apothecia themselves often with isidia, lacking soredia. Most similar morphologically to P. squarrosa which is expected to be corticolous and rarely saxicolous, thus roughly of opposite substrate preference of P. saxatilis, but P. saxatilis has simple to forked rhizines below while P. squarrosa has squarrose rhizines (Brodo et al. 2001).

Substrate #

saxicolous, uncommonly corticolous

Chemical Tests #

upper cortex: K+ yellow, C-, KC-, Pd+ yellow; medulla: K+ yellow becoming red, C-, KC-, Pd+ orange (CLH)

Notes #

Nearly ubiquitous in Alaska, few records along or near the Yukon River (CLH).