Epiphytic Crustose Lichens of the Clearwater Valley, British Columbia

Melaspilea

Crustose lichens containing a trebouxioid or trentepohlioid alga; thallus immersed in wood grains, often with a few granules at the surface; apothecia jet black, round or lirelloid, sometimes branched; disc exposed or slit-like; rim non-algal, formed of tangled hyphae, pigmented dark brown throughout; hymenium formed of straight, thin, sparsely branched and anastomosed paraphyses embedded in gel; hypothecium colourless or brown; asci narrowly clavate, with a thin, IKI- tholus, with an ocular chamber; spores 8 per ascus, light brown at maturity, 1-septate, generally constricted at the septum, sometimes with a minutely warty outer layer.

References: Purvis et al. 1992; Ryan & Nimis 2004.

Melaspilea obesispora Björk ined.

Thallus immersed, inconspicuous, with a few brownish or whitish granules emerging to the surface, containing a trebouxioid alga; apothecia 0.2-0.3 × 0.08-0.1 mm, with a black, thin, persistent rim, the disc slit-like, somewhat glossy; exciple dark reddish brown as seen in section; hymenium 40-50  µ high, dark brown in upper portions; spores 12-17 × 7-10  µ.

Reactions: Spot tests all negative.

Contents: Unknown.

Habitat: On wood of exposed Pseudotsuga root on a trail bank on a limestone slope, middle elevations.

Similar Species: Ptychographa and Xylographa may appear similar, but have colourless, simple spores.

Specimens: Björk 15157.

Local Status: Rare.

Notes: Known only from a single locality just outside the study area.