E-Flora BC: Electronic Atlas of the Flora of British Columbia

General:
Common Name: The Starburst Lichens. Describes the centrifugal growth pattern characteristic of the species
Small to medium stratified foliose lichens, corticate above and below, isidiate (in BC), lobes closely appressed, elongate, averaging to 1–2 mm wide, thin. Upper surface whitish, shiny. Lower surface whitish to pale brown, bearing short, simple rhizines. Medulla white. Photobiont green.
Apothecia located over upper surface, disc brownish; spores simple, ellipsoid, colourless, 8 per ascus.
Over conifer bark.
Notes: Imshaugia is a temperate-boreal genus with two species worldwide. Both occur in North America, though only one occurs in B.C. Imshaugia was formerly treated within Parmeliopsis. For points of distinction with similar species in other genera, see the descriptions under that genus.

Reactions:
Cortex K+ yellow; medulla PD+ yellow becoming reddish.

Contents:
Atranorin and thamnolic acid.