Pycnora
Crustose lichens containing a trebouxioid alga; thallus areolate, squamulose, verrucose, sorediate or smooth; apothecia thin, jet black, with a thin but prominent and persistent rim that usually remains higher than the disc; rim formed of globose or elliptical cells coated in dark brown pigment, continuous and dark pigmented below the hypothecium; hymenium colourless except in upper portions, formed of gel-embedded, slightly gnarled, seldom branched paraphyses with dark pigments in the slightly swollen tips; hypothecium colourless; asci broadly clavate to clavate, with a modestly thickened tholus that reacts IKI+ medium blue with a broad axial mass that reaches through the entire height of the tholus; spores 8 per ascus, colourless, simple, elliptical.
References: Timdal 1984; Hafellner & Türk 2001; Timdal 2002.
| 1a. | Thallus lacking soredia, thallus C-, K-, PD …Pycnora elachista ined. |
| 1b. | Thallus with soredia, C+ orangish pink, K+ yellow, PD+ yellow …2 |
| 2a. | Squamules solitary or few together, often slightly lobate, with marginal soralia; common on twigs and branches, less often on trunks, usually on bark …Pycnora leucococca |
| 2b. | Thallus forming dense, continuous patches of areoles with apical soralia; uncommon, on wood …Pycnora sorophora |
Pycnora elachista Björk ined.
Thallus smooth, grey or brownish grey, waxy, often immersed or poorly formed, lacking soredia; apothecia ever present, often crowded, 0.2-0.5 mm wide; upper hymenium medium to dark brown, K-, K+ olive, or K+ reddish purple; hypothecium colourless, thin; asci dense; spores 10-15 × 6-8.5 µ.
Reactions: Spot tests all negative.
Contents: No lichen substances found in TLC.
Habitat: On bark or wood of conifer branches and twigs, always above the winter snowpack, middle elevation forests.
Similar Species: May appear somewhat like Buellia punctata, which has brown, one-septate spores and thicker apothecia.
Local Status: Rare.
Notes: Very common and widespread in boreal BC, Alberta and Alaska, scattered southward in dry or subalpine forests.
Pycnora leucococca (R. Sant.) Hafellner in Hafellner & Türk
Thallus of scattered clusters of squamules and areoles, creamy white or pale bluish white, with marginal soralia usually positioned at the tip rather than the sides of the areoles; soredia coloured like the areoles, 20-45 µ wide; apothecia not produced.
Reactions: C+ red, K+ yellow, PD+ yellow.
Contents: Alectorialic acid and related substances.
Habitat: On conifer bark or wood above the winter snowpack. All forested elevations.
Similar Species: Only Rinodina degeliana (a species of lower elevations) is similar; it lacks the C+ red reaction.
Local Status: Occasional.
Pycnora sorophora (Vainio) Hafellner
Thallus areolate, verrucose, or immersed with scattered areoles rising to the surface, producing soredia early in development, becoming entirely sorediate, the thallus and soredia creamy yellow or creamy yellow-green, turning brown in exposed parts, matte; apothecia rare, 0.3-0.6 mm wide, jet black, with a thin but persistent rim, the disc remaining flat; rim interior dark brown throughout, even under the hypothecium; hymenium 55-70 µ high, dark grey-green or olive-brown in upper portions; hypothecium dark brown; spores elliptical, 6-9 × 2.5-4.5 µ.
Reactions: K+ deep yellow, C+ pink (flash), KC+ red, PD+ deep yellow-orange.
Contents: Alectorialic acid and xanthococca unknown.
Habitat: On dry, hard conifer wood, rarely on bark, in well ventilated, well lit forests. All forested elevations.
Similar Species: Except for Pycnora leucococca, which is easily distinguished on morphological characters, no other sorediate species in the study area has the strong K,C, and PD spot test reactions.
Specimens: Goward 78-384.
Local Status: Rare.