Ochrolechia
Crust lichens containing a trebouxioid alga; thallus smooth, areolate, cracked, verrucose, granular, isidiate, or sorediate; apothecia usually with a very thick algal rim that resembles the thallus more than the disc, often also with an inner rim that resembles the disc in colour and texture, the disc yellowish orange to salmon pink; the rim containing a thick, white, spongy medulla; hymenium formed of thin, branched and anastomosed paraphyses embedded in gel, often densely inspersed with crystals; hypothecium colourless; asci thick-walled, oblong, IKI+ blue only in a haze around the exterior, the apex not much thickened, but with a distinct, broad ocular chamber; spores 2-8 per ascus, colourless, simple, somewhat thick-walled, broadly elliptical.
References: Brodo 1991; Purvis et al. 1992; Spribille 2006.
| 1a. | Thallus sorediate; apothecia often absent …2 |
| 2a. | Soredia and crust C-, usually UV+ yellow-orange; crust thick and verrucose, matte white or creamy whitish, apothecia usually abundant …Ochrolechia farinacea |
| 2b. | Soredia and/or crust C+ pink or red; UV- or +; thallus various; apothecia usually absent …3 |
| 3a. | Crust C-, but the soredia C+ pink or red …4 |
| 4a. | Crust distinctly darker than the soralia, usually thin and smooth, always C-; soralia mostly flat or concave, mostly remaining distinct; soredia farinose (compared to O. androgyna); apothecia pruinose; mostly subalpine or in cold areas in lowland forest …Ochrolechia gowardii |
| 4b. | Crust concolorous with the soralia, usually thick and verrucose, C- or C+ red; soralia mostly convex, becoming confluent with age; soredia granular; apothecia not particularly pruinose; a highly variable species in a wide variety of habitats …Ochrolechia androgyna |
| 3b. | Crust, as well as the soredia C+ pink or red …5 |
| 5a. | Thallus UV+ yellow or orange, containing lichexanthone; thallus usually covering areas less than 1 cm wide; to be sought …[Ochrolechia arborea (Kreyer) Almb.] |
| 5b. | Thallus UV- or UV+ blue-white, lacking lichexanthone; thallus usually covering areas more than 1 cm wide at maturity …6 |
| 6a. | Thallus C+ deep pure red; apothecia common (but often concealed beneath soredia), without a distinct rim, easily recognized as a round patch of evenly spaced orange-tan dots (the individual asci are recognizable at 10x); spores 2-celled, 200-400 × 70-140 µ …Varicellaria rhodocarpa |
| 6b. | Thallus C+ pink-red; apothecia rare, with a thick, donut-like rim, the asci too small to see at 10x; spores 30-45 × 13-22 µ; widespread …Ochrolechia androgyna |
| 1b. | Lacking soredia, always fertile …7 |
| 7a. | Apothecial rim C- or C+ yellow in both the cortex and medulla …8 |
| 8a. | Apothecial disc C- or C+ yellow not red or pink, with thick pruina so heaped up as to give the disc a bumpy surface; thallus thin or immersed, usually smooth …Ochrolechia szatalaënsis |
| 8b. | Apothecial disc C+ obviously red or pink, with a thin pruina usually not is so heaped up as to give the disc a roughened appearance; thallus almost always thick and usually verrucose …Ochrolechia juvenalis |
| 7b. | Apothecial rim C+ pink to red …9 |
| 9a. | Apothecial rim with only a single layer that resembles the crust in colour and texture (check both young and old apothecia to be sure); rim white-medullary throughout except for very few algal cells in scattered clusters, lacking a distinct algal ring or layer; thallus thin and smooth …Ochrolechia laevigata |
| 9b. | Apothecial rim with a ring of salmon-pink tissue that resembles the disc in colour and texture, this in addition to an outer ring of thalline tissue that resembles the crust in colour and texture …10 |
| 10a. | Apothecia 0.7-2 mm across, but mostly less than 1.5 mm, widely scattered and evenly spaced; rim usually of even width throughout and remaining intact; crust thin and smooth or slightly verrucose …Ochrolechia montana |
| 10b. | Apothecia 1-4.5 mm across, but mostly more than 1.5 mm, usually clustered; rim usually lumpy and brittle; thallus thick and verrucose; spores 50-75 × 28-41 µ …Ochrolechia oregonensis |
Ochrolechia androgyna (Hoffm.) Arnold
Thallus creamy white or (less often) bluish white, continuous, thick, with concave to flat soralia 0.5-1 mm wide; soredia coloured like the thallus, granular, about 50 µ wide; apothecia rare, 0.5-2.5 mm thick, the rim weakly corticate and often producing soredia; spores 30-45 × 13-22 µ
Reactions: Soredia and apothecia, and usually also the crust, C+ red, KC+ red, sometimes K+ yellowish.
Contents: Gyrophoric acid and minor amounts of lecanoric acid and unknown fatty acids.
Habitat: On bark and wood above the winter snowpack. All forested elevations.
Similar Species: Ochrolechia arborea may appear similar, but differs in having more characteristically convex soralia, and a UV+ yellow thallus.
Specimens: Björk 12315; Goward 94-888, 96-767.
Local Status: Uncommon.
Ochrolechia farinacea Howard
Thallus thick, verrucose to bullate-areolate, with a weak, matte cortex that often disintegrates, revealing the medulla and allowing production and proliferation of soredia, creamy white or or pure white; apothecia usually present, 1-3 mm wide, the margins thick, with the colour and texture of the thallus, the disc coarsely pruinose-scabrous, yellowish pink or red-orange; rim with a well-defined algal layer continuous below the hypothecium, inner rim absent; hymenium 230-300 µ high; spores 44-65 × 21-35 µ, 2-5 per ascus.
Reactions: Thallus and apothecial rim C- or + yellow; apothecial disc C+ yellow.
Contents: Variolaric, murolic, and neodihydromurolic acids, and an unidentified UV + yellow-orange substance.
Habitat: On rough bark in very humid sites. Lower elevations.
Similar Species: Some forms of Varicellaria rhodocarpa are similar, but react C+ deep red.
Specimens: Björk 8666.
Local Status: Rare.
Ochrolechia gowardii Brodo
Thallus creamy grey, less often creamy whitish, thin, continuous, with concave to flat soralia 0.5-1 mm wide; soredia creamy white, usually distinctly paler than the crust, 40-50 µ wide; apothecia uncommon, 0.6-1 mm wide; spores 45-65 × 22-33 µ.
Reactions: Soredia and apothecia (but not the crust) C+ red.
Contents: Gyrophoric and lecanoric acid in the soralia and apothecia, and variolaric acid in the apothecia.
Habitat: On smooth bark of conifer trunks above the winter snowpack, less often on snags. Middle to upper forested elevations.
Similar Species: Ochrolechia androgyna and O. arborea have a thicker, paler crust that reacts C+ red, and O. arborea is UV+ yellow.
Specimens: Goward 05-25.
Local Status: Uncommon.
Notes: This species is endemic to the Columbia and Rocky Mountains in BC, Idaho and Montana.
Ochrolechia juvenalis Brodo
Thallus usually coarsely warty in mature portions and smooth around the edges, or sometimes smooth throughout, creamy white or grey; apothecia mostly evenly spaced, sometimes crowded, 0.8-1.5 mm wide, the rim thick, prominent and persistent (donut-shaped), coloured like the thallus, the disc yellow-orange or pink-orange, usually covered by a coarse accumulation of pruina; rim algal, with a thick, cottony medulla, also with a thick proper exciple lining the disc; hymenium 230-270 µ high, colourless; upper hymenium thickly granular; hypothecium colourless, the layer below usually with a few clumps of algae; spores usually 8 per ascus, 38-65 × 20-33 µ.
Reactions: Thallus and apothecial thallin rim C- or C+ yellow, the disc K+ deep yellow, C+ orange-red, KC+ red.
Contents: Gyrophoric (in the disc), variolaric and lichesterinic acid.
Habitat: On bark of conifer branches. Lower to middle elevations, rarely at upper forested elevations.
Similar Species: Ochrolechia oregonensis is C+ red in the thallus and apothecial rim and is usually much larger in all parts. Ochrolechia szatalaensis may appear very similar, but usually has a smoother thallus and is C- or C+ yellow in the disc.
Specimens: Goward 94-920.
Local Status: Occasional.
Ochrolechia laevigata (Räsänen) Vers. ex Brodo
Thallus thinner than most other Ochrolechia, smooth, waxy, yellowish grey or creamy whitish; apothecia 1.2-3 (‑4) mm wide, individually scattered, the rim moderately thick, smooth, coloured like the thallus or paler, the algal layer sparse and discontinuous, lacking an inner rim, the disc lacking pruina, slightly rough, yellowish pink or pale orange; hymenium 300-400 µ high; spores 34-52 × 20-26 µ, 6-8 per ascus, often poorly defined.
Reactions: Thallus C- or C+ pink, apothecial rim C+ pinkish red, disc C+ red.
Contents: gyrophoric and olivetoric acids and ± lecanoric and 4-O-demethylmicrophyllinic acids.
Habitat: On smooth bark of Alnus in humid, cool, well-lit sites along rivers. Lower elevations.
Similar Species: Ochrolechia montana also has a thin, smooth thallus, but produces a pinkish inner apothecial rim in addition to the thalline rim.
Specimens: Goward 01-648.
Local Status: Uncommon.
Ochrolechia montana Brodo
Thallus thinner than most other Ochrolechia, smooth, waxy or matte, yellowish grey; apothecia 0.7-1.8 mm wide, individually scattered, the rim smooth, with an outer rim coloured like the thallus and an inner rim more like the disc in colour and texture, the algal occurs in layer in the outer rim and is discontinuous below the hymenium; hymenium 210-250 µ high; spores 35-55 × 19-27 µ, usually 8 per ascus.
Reactions: Apothecial rim and sometimes also the thallus C+ pink, KC+ red, the disc C+ pink, KC+ red.
Contents: Gyrophoric acid and ± lobaric acid and an unknown.
Habitat: On more or less smooth bark, usually on conifer trunks, especially at upper forested elevations.
Similar Species: See notes under Ochrolechia laevigata.
Specimens: Goffinet 3726.
Local Status: Rare.
Ochrolechia oregonensis H. Magn.
Thallus thick, coarsely warty and granular, pale greenish or bluish grey, lacking soredia; apothecia common and abundant, 1.5-4.5 mm wide, with a very thick, warty and fissured thalline rim, and a non-thalline, pink-orange inner rim that resembles the disc in colour and texture; disc pink-orange; spores 50-75 × 28-41 µ.
Reactions: Cortex C+ and KC+ red.
Contents: Gyrophoric acid and minor amounts of lecanoric acids and unknown fatty acids.
Habitat: Rough bark of conifer trunks above the winter snowpack. Lower to middle elevations.
Similar Species: This species is distinctive in having the combination of a very thick thallus, warty and fissured thalline rim in combination with a pink-orange inner rim, and in growing on rough bark.
Specimens: Goward 94-887, 96-830, 96-1215.
Local Status: Common.
Ochrolechia szatalaënsis Vers.
Thallus creamy white, thin, continuous and smooth or slightly lumpy, sometimes immersed, lacking soredia; apothecia everpresent, 1.5-2.5 mm wide at maturity, the rim thalline, moderately thick, lacking a non-thalline inner rim; disc yellow-orange, covered in dense, crystalline pruina; spores 45-65 × 25-38 µ.
Reactions: C- or C+ yellow.
Contents: Variolaric acid, and minor amounts of murolic and neodihydromurolic acids.
Habitat: On bark of branches and twigs above the winter snowpack, less often on wood or on trunks. All forested elevations.
Similar Species: Ochrolechia juvenalis is similar in appearance and may be found in upper forested elevation forests, but has C+ red apothecial discs.
Specimens: Björk 8656, 10900; Goward 94-914, 02-04.
Local Status: Common.
References: Brodo (1991).