Bactrospora brodoi

Bactrospora brodoi is a corticolous (bark-dwelling) crustose lichen of uncertain family placement in the order Arthoniales. Described in 1993 by José María Egea and Pilar Torrente and named for the Canadian lichenologist Irwin M. Brodo, it forms a very thin, mostly immersed pale film with tiny black, rimless discs and produces very slender, many-celled ascospores; a conspicuous asexual stage with larger pycnidia is frequent in Fennoscandia and parts of eastern Canada. The species is rare and boreal, known from eastern Canada and Fennoscandia, with a doubtful outlier reported from coastal California. It favours long-continuity, humid spruce forests, especially the dead, bark-covered lower twigs of very old Norway spruce (Picea abies); in Canada it also occurs on yellow birch (Betula alleghaniensis) and eastern white-cedar (Thuja occidentalis) in swampy stands. Forestry that removes veteran host trees or dries these habitats is the main threat; it is assessed as critically endangered in ......read more on Wikipedia.