“Mycomicrothelia”
Unlichenized fungi living as part of epiphytic crust lichen communities, or occasionally with a loosely lichenized trentepohlioid alga; thallus thin or immersed, inconspicuous; perithecia flat to more or less globose, black, the wall not extending below the hymenium, formed of entwined hyphae incorporating bark fragments; hymenium of branched and anastomosing hyphae embedded in gel, the gel I- or I+ purple; asci narrowly to broadly clavate, with a modestly thickened tholus having an ocular chamber, IKI-; spores colourless, 8 per ascus, shaped like the sole of a shoe, having one half longer and wider than the other, and being constricted at the single septum, occasionally secondary transverse septae forming late in development.
References: Purvis et al. 1992.
“Mycomicrothelia” conspicua Björk ined.
Thallus immersed, inconspicuous, lacking algae; perithecia black, about 1.5 × wide as high; asci cylindric-elliptic; spores with a warty outer layer, lacking a gelatinous perispore, light brownish, at least at overmaturity, 1-septate except some secondary walls present in overmature spores, 22-31 × 7-10.5 µ.
Reactions: Spot tests all negative.
Contents: Unknown.
Habitat: On Populus trichocarpa bark. Lower elevations.
Similar Species: Arthopyrenia populicola is very similar, but has smooth-walled spores and clavate asci.
Local Status: Occasional.
Notes: Known only from inland BC.