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

Trevor Goward,Leena Myllys

doi:10.35535/pfsyst-2020-0017

Abstract

The fruticose lichen genus Gowardia (Parmeliaceae) was recently segregated from Alectoria based on phylogeny, morphology, secondary chemistry, ecology and distribution. As currently circumscribed, Gowardia comprises two wide-ranging species of arctic-alpine regions. Here we describe a third species, G. zebrina sp. nov., apparently endemic to subalpine regions in mountainous northwestern North America. Gowardia zebrina 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 A. nigricans suggests the existence of several additional undescribed species of Gowardia. A brief overview of morphological diversity in these species is given, shedding new light on the question of whether Gowardia should be subsumed under Alectoria, as some have suggested, or is more appropriately recognized as a distinct genus.

Highlights

In 2009 the fruticose lichen genus Gowardia (Parmeliaceae, Lecanoromycetes) was segregated from Alectoria on the basis of morphology, cortical chemistry, habitat ecology, distribution and phylogeny (Halonen et al 2009; see Miadlikowska et al 2014 and Myllys et al 2014)
The recent discovery of a putative third species of Gowardia in the Coast Mountains of western Canada prompted a careful morphological review of material filed under Alectoria nigricans at the UBC herbarium in Vancouver, British Columbia
An important finding of our study is that Gowardia is likely a much more speciose genus than currently recognized: far from encompassing only two species worldwide, more than a dozen Gowardia species appear to be present in North America alone

Summary

Introduction

In 2009 the fruticose lichen genus Gowardia (Parmeliaceae, Lecanoromycetes) was segregated from Alectoria on the basis of morphology (pseudocyphellae plane versus raised, respectively), cortical chemistry (usnic acid versus alectorialic acid), habitat ecology (mostly epiphytic versus mostly terrestrial), distribution (mostly arctic-alpine versus mostly temperate-boreal) and phylogeny (Halonen et al 2009; see Miadlikowska et al 2014 and Myllys et al 2014). Two species of Gowardia are currently accepted, both restricted to open, windswept habitats in arctic-alpine regions (Halonen et al 2009). Gowardia arctica ranges across northern Canada and Russia (Halonen et al 2009). Gowardia nigricans is more widespread, reported from arctic-alpine regions of both the Northern Hemisphere and Southern Hemisphere (Hawksworth 1972; Galloway 2007). The recent discovery of a putative third species of Gowardia in the Coast Mountains of western Canada prompted a careful morphological review of material filed under Alectoria nigricans at the UBC herbarium in Vancouver, British Columbia. In this paper we have four objectives: (1) to formally describe our new species

Methods

Results

Conclusion