New taxa and a case of ephemeral spore production in Lecideaceae from western North America

摘要

Cyclohymenia epilithica is a newly described genus and species from Oregon and Washington, U.S.A. It occurs on noncalcareous rock in the oceanic forests west of the crest of the Cascade Range. Unlike most other North American species in the Lecideaceae, it is restricted to shady habitats in cool, wet, temperate climates. It is distinguished from other members of the family by its thick, pale gray green, epilithic thallus; immersed apothecia that superficially appear like perithecia or pycnidia; and ascocarps that usually contain a central sterile column surrounded by a ring-shaped hymenium. The structure and position of the ascocarp appear to be unique among Lecideaceae and related families. The species is also unusual in producing short-lived asci; most collections have barren apothecia. Lecidea atrobrunnea subsp. deplanaica is raised to the species level. The taxon deserves specific rank, not just from its distinctive chemistry, but also from morphology, distribution, and ecology that differ from L. atrobrunnea s.str. The newly described Lecidea uniformis from Oregon and Washington, mainly west of the Cascade crest, is similar in many ways to L. fuscoatra, but the areoles are uniformly brown and do not have a differentiated gray, blackish, or whitish edge. DNA sequence data support the taxa Cyclohymenia epilithica and L. uniformis.