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

General:
Common Name: The Bone Lichens. Stresses the hollow lobes of the species and the pale, often whitish, upper cortex.
Small to medium stratified foliose lichens, corticate above and below, sorediate or rarely isidiate or not, lobes rather loosely appressed to semi-erect or pendulous, hollow, occasionally perforate, 0.5–5 mm wide. Upper surface usually pale greyish, occasionally brownish. Lower surface blackish, shiny, wrinkled, lacking rhizines. Medulla white. Photobiont green.
Apothecia located over upper surface, often stalked/stipitate, disc usually concave, brown; spores simple, spherical to ellipsoid, colourless, 8 per ascus.
Notes: Hypogymnia is essentially a temperate genus of about 50 species worldwide. Twenty species occur in North America and 17 in B.C. The western Hypogymniae display a highly varied chemistry and spot tests are helpful in distinguishing between species. Note that what is usually referred to as a PD- medullary reaction in Hypogymnia may sometimes actually be discerned as PD+ pale yellow. In this case, however, the coloration is usually restricted to the upper portion of the medulla, while the lower portion remains white. By contrast, a “true” PD+ pale yellow reaction (e.g., as for H. rugosa) registers across the entire medulla, from top to bottom. Applying as little reagent as possible will help avoid ambiguity. Brodoa oroarctica was formerly treated within Hypogymnia.

Species description:
Soredia present (check lobe tips) AND
Soredia located on upper surface (including upper surface of lobe tips) AND
Lobes distinctly swollen, bearing (basally constricted) marginal lobules; lobe tips often perforate; medulla PD+ yellow becoming bright orange; essentially coastal

Comments:
The type locality is near Sutton Pass on southern Vancouver Island, B.C.

Reactions:
Cortex K+ yellow; medulla KC+ red, PD+ orange.

Contents:
Atranorin, physodic, physodalic and protocetraric acids.