Hypocenomyce
Mesolichens or crust lichens containing a trebouxioid alga; thallus squamulose or areolate, sometimes lobate, brown, grey, olive or beige; apothecia black or greyish black, with a thin but prominent and persistent, non-algal rim; the rim formed of rounded cells or cylindrical hyphae, dark-pigmented in outer portions or throughout; hymenium colourless except in upper portions, which have an olive or blackish brown pigment, formed of mostly straight, unbranched paraphyses embedded in gel; hypothecium colourless; asci clavate or elliptical, with a thin tholus that is IKI- or + light to medium blue, often with a darker blue tube (appearing as two parallel lines running up the length of the tholus), but most often, the asci are poorly developed, with a scarcely observable tholus and weak IKI stain; spores colourless, 8 per ascus, non-septate or with 1-3 septae, elliptical to fusiform, often poorly formed.
References: Timdal 1984, 2001.
| 1a. | Squamules mostly adnate, few ascending at the edges, lacking soredia; apothecia usually present …2 |
| 2a. | Squamule cortex K+ yellow, PD + yellow, C+ red, KC+ red (rarely C- or KC‑); apothecia with only an exterior rim and central disc, not gyrose; asci usually not maturing and not developing an apical dome; to be sought …[Hypocenomyce oligospora Timdal] |
| 2b. | Squamule cortex K-, PD-, C-, KC-; gyrose or not; asci maturing or not …3 |
| 3a. | Medulla K+ yellow, PD+ pale yellow, C+, KC+ red; thallus bullate; apothecia quickly becoming gyrose; asci rarely maturing; Growing on charred wood …Hypocenomyce bullata ined. |
| 3b. | Medulla K-, PD-, C-, KC-; thallus of flat to low-convex squamules; apothecia gyrose or not; asci maturing; very common in wet forests, especially on Thuja, seldom on charred wood or bark …Hypocenomyce friesii |
| 1b. | Squamules almost always ascending on one side, usually with soredia on the underside and/or on the margins; apothecia usually absent …4 |
| 4a. | Squamules matte, usually creamy whitish or tan, the cortex C+ deep red; apothecia black; very common in our area …Hypocenomyce scalaris |
| 4b. | Squamules waxy or glossy, usually greyish brown or dark brown, the cortex C-; apothecia medium brown or black …5 |
| 5a. | Squamules olive to medium brown, with a distinctly paler margin, more or less concave when young; cortex and soredia PD+ orange/red; apothecia usually simple and round, usually with a thin but distinct rim …Hypocenomyce anthracophila |
| 5b. | Squamules golden brown, margin not or only weakly paler, more or less convex when young; cortex and soredia PD-; apothecia usually becoming botryoid, usually without an evident rim …Hypocenomyce castanocinerea |
Hypocenomyce anthracophila (Nyl.) P. James & Gotth. Schneider
Thallus formed of squamules 0.3-0.8 (‑1.3) mm wide, mostly ascending on one side, greenish brown to medium brown, shiny, the lifted edge lined with medium to dark grey soredia; apothecia uncommon, 0.4-1.3 mm wide, with a thin, slowly receding rim, the disc coloured like the rim or slightly darker, remaining simple; hymenium 40-50 µ high, light to medium brown in upper portions; hypothecium colourless; spores narrowly elliptical, simple or a few 1-septate, 7-13 × 1.5-2.5 µ.
Reactions: Cortex PD+ red, medulla and soredia KC+ purple, PD+ red.
Contents: Fumarprotocetraric and protocetraric acids, and anthracophila unknowns.
Habitat: On charred wood of snags. All forested elevations.
Similar Species: Hypocenomyce castanocinerea may appear very similar, but the spot tests make distinguishing these two very easy.
Specimens: Björk 10845, 12828.
Local Status: Occasional.
Hypocenomyce bullata Björk ined.
Thallus of bullate areoles that are constricted at the base, rarely lifting on one side and becoming subsquamulose, medium to dark brown, glossy; apothecia abundant, jet black, with a thin but persistent rim, older apothecia gyrose rather glossy, gyrose, with excipular material proliferating through portions of the disc; hymenium 15-25 µ high, light brown throughout, the paraphyses formed of shortly cylindrical cells 1-3 × long as wide; hypothecium opaque dark brown; asci poorly formed; spores rare, elliptical, about 5 × 2.5 µ, simple.
Reactions: Medulla K+ yellow, C+ red, KC+ red, PD+ pale yellow
Contents: Unknown.
Habitat: On charred wood in Populus-Betula-Picea stands. Lower elevations.
Similar Species: Hypocenomyce caracodensis, which is known elsewhere in BC, is very similar, but lacks positive spot test reactions in the areole medulla, and have non-gyrose or rarely gyrose apothecia. Hypocenomyce oligospora has a C+ and KC+ red cortex, non-gyrose apothecia, and larger spores.
Specimens: Björk 17829.
Local Status: Rare.
Notes: Known only from the study area.
Hypocenomyce castanocinerea (Räsänen) Timdal
Thallus of greenish brown to deep brown, shiny squamules 0.3-0.8 (‑1.3) mm wide, ascending, the lifted edge with grey soredia; apothecia rare, 0.3-0.5 (‑0.7) mm wide, dark brown, with a very poorly formed excipular rim that quickly recedes, the disc becoming low to high-convex, often botryoid; hymenium colourless, except brown in upper portions; hypothecium colourless; asci poorly formed; spores usually not matured, 7-13 × 2-2.5 µ, narrowly elliptical, simple.
Reactions: Medulla KC+ purplish pink.
Contents: Anthracophila unknowns 1, 2, 3, and 4.
Habitat: On charred wood in lower to middle elevation forests.
Similar Species: Hypocenomyce anthracophila produces different spot test reactions, and differs subtly.
Specimens: Björk 10772; Goward 83-686, 96-08.
Local Status: Occasional.
Hypocenomyce friesii (Ach.) P. James & Gotth. Schneider
Thallus squamulose, sometimes lobate, the squamules and lobes flat to moderately convex, about 0.5-1 mm wide, not or scarcely lifting from the substrate, medium green-brown or orangish brown, glossy; apothecia jet black, moderately glossy, with a thin but persistent rim, the disc flat or low-convex, becoming gyrose with age; hymenium colourless except brown in upper portions; hypothecium pale to dark brown; asci frequently maturing; spores 4.5-7.5 × 2.5-3.5 µ, simple, elliptical.
Reactions: Spot tests all negative.
Contents: Friesii unknowns.
Habitat: On Thuja bark or on hard wood of snags in humid forests, often in deep shade where few other lichens grow. All forested elevations.
Similar Species: Hypocenomyce caracodensis is very similar, differing in having bullate (higher-convex) areoles that are less glossy, and produces short-celled paraphyses, and both simple and septate spores. Hypocenomyce oligospora should be sought. It differs in having squamules K+ yellow and PD+ yellow, and non-gyrose apothecia.
Specimens: Björk 9516.
Local Status: Common.
Hypocenomyce scalaris (Ach.) M. Choisy
Thallus of ascending squamules, light to medium grey-olive, clam-shell shaped, 0.8-1.2 mm long and wide, almost always entire and not incised along the rim, the lower surface at the rim producing abundant soredia; apothecia uncommon, 0.5-1.5 mm wide, jet black, usually matte and with a light dusting of greyish pruina, the rim thin but prominent and persistent, the disc remaining flat, lacking concentric ridges, but sometimes with a single button-like ring of accessory rim tissue in the center; hymenium 45-60 µ high; upper hymenium brownish green; hypothecium medium to dark brown; asci usually malformed; spores very rare and always malformed.
Reactions: Thallus K-, C+ red (flash), KC+ red, PD-.
Contents: Lecanoric acid, plus unknown substances.
Habitat: Snags and large trunks, especially Pseudotsuga. All forested elevations.
Similar Species: Some Cladonia species produce squamules with soredia on the underside, but would not be grey olive, nor react C+ or KC+ red.
Specimens: Goward 01-229.
Local Status: Common.