Gowardia zebrina sp. nov., a new species in a little-known genus of arctic-alpine lichens (Parmeliaceae)

<b>Abstract</b><br/><p>The fruticose lichen genus <em>Gowardia</em> (Parmeliaceae) was recently segregated from Alectoria based on phylogeny, morphology, secondary chemistry, ecology and distribution. As currently circumscribed, <em>Gowardia</em> comprises two wide-ranging species of arctic-alpine regions. Here we describe a third species, <em>G. zebrina </em>sp. nov., apparently endemic to subalpine regions in mountainous northwestern North America. <em>Gowardia</em> <em>zebrina</em> differs from other species in the genus by its combined subpendent habit, uniformly capillary branches, predominantly isotomic branching, pale-and-dark banding of the terminal branches, and epiphytic ecology. Morphological examination of North American herbarium specimens filed under <em>A. nigricans</em> suggests the existence of several additional undescribed species of <em>Gowardia</em>. A brief overview of morphological diversity in these species is given, shedding new light on the question of whether <em>Gowardia</em> should be subsumed under <em>Alectoria</em>, as some have suggested, or is more appropriately recognized as a distinct genus.</p>