Micarea
Crustose lichens, algae trebouxioid or micareoid (3-7 µ, rounded-polygonal, without easily observed internal structure, tending to be grouped in small clusters); thallus smooth, verruculose, granular, areolate, or goniocystose; apothecia essentially rimless or, in a few species, with a thin but conspicuous rim formed of tangled, densely branched hyphae; hymenium of gnarled, branching (but not often anastomosing) paraphyses embedded in gel, these usually thin at the tips, upper hymenial layers sometimes with granules, often with minute POL+ white crystals throughout (gyrophoric acid); hypothecium pale or variously pigmented; asci clavate, with a well developed tholus that reacts IKI+ light to dark blue and with a darker blue tube (that appears like a pair of parallel lines); spores 8 per ascus, colourless, simple or with 1-several transverse septae, elliptical, oblong, ovate, bacilliform or fusiform.
References: Coppins 1983; Coppins & Tønsberg 2001; Spribille 2006; Fryday & Coppins 2007.
| 1a. | Upper hymenium light to medium grey or brown, K+ mauve or pinkish …2 |
| 2a. | Spores mostly 3 septate (a few with 1, 2, 4 or 5 septae intermixed) …3 |
| 3a. | Older apothecia developing a thin but dense layer of grey pruina; young apothecia with a distinct rim well distinguishable from the disc; spores 16-32 × 2-3 µ …“Bacidia” beckhausii |
| 3b. | Apothecia never pruinose; apothecia rimless, or with an indistinct rim that is confluent with the disc; spores various …4 |
| 4a. | Apothecia medium to dark greyish brown, often tuberculate; pycnidia conspicuous, with a black stalk and white tip, usually abundant; ascospores (10.5‑) 14-19 × 2-2.8 µ; common in humid forest …Micarea silvae-veteris |
| 4b. | Apothecia black, or grey in deeply shaded forms, rarely tuberculate; pycnidia inconspicuous, lacking a stalk; ascospores 13-26 × 2-2.5 µ; to be sought …[Micarea globulosella (Nyl.) Coppins] |
| 2b. | Spores simple or 1-septate (rare spores 2- to 3-septate) …5 |
| 5a. | Thallus with smooth, adnate areoles, of if granular, then granules firmly corticate, or (rarely) thallus immersed …Micarea denigrata |
| 5b. | Thallus of goniocystose granules, lacking any firmly corticate portions, not immersed …6 |
| 6a. | Stalked pycnidia present; thallus and apothecia lacking gyrophoric acid, POL-; thallus never leprose; spores 10-19 × 2-2.8 µ, usually with a majority of spores 3-septate; common in humid forests …Micarea silvae-veteris |
| 6b. | Stalked pycnidia lacking; gyrophoric acid present or absent; spores wider than in 6a …7 |
| 7a. | Thallus and apothecia usually with gyrophoric acid, C+ in section; spores 8-14 × 2.5-5 µ …Micarea prasina |
| 7b. | Thallus and apothecia with methoxymicareic acid, C-; spores 8-14 × 2.5-4 µ …Micarea micrococca |
| 1b. | Upper hymenium K- or K+ various reactions, if K+ mauve, then pigment purplish before reacting to K …8 |
| 8a. | Spores with 3 or more septae; apothecia and/or thallus usually C+ reddish (LM) …9 |
| 9a. | Hypothecium with distinctly opaque dark brown green-brown or purple-brown pigments; apothecia jet black …Micarea melaena |
| 9b. | Hypothecium either colourless, or pigmented with pale to medium tones, translucent; apothecia colour various …10 |
| 10a. | Spores with (3‑) 5-7 septae, (19‑) 23-34 (‑38) × 4.5-6 µ; hymenium 55-70 µ high; apothecia creamy whitish to medium or dark grey; to be sought …[Micarea cinerea (Schaerer) Hedl.] |
| 10b. | Spores with (0‑) 3 (‑5) septae, averaging shorter; hymenium 40-55 µ high; apothecia colour various …11 |
| 11a. | Apothecia 0.2-0.7 mm wide, creamy whitish, usually crowded in groups; spores (16‑) 18-26 (‑30) × (4‑) 4.5-5 (‑6) µ …Micarea alabastrites |
| 11b. | Apothecia 0.15-0.4 (‑0.6) mm wide, creamy whitish to medium or dark grey, usually solitary or paired, occasionally grouped; spores (11‑) 15-24 × 3-5 (‑6) µ …Micarea peliocarpa |
| 8b. | Spores with 0-1 septae, or occasionally with few spores intermixed having 2-3 septae; apothecia and thallus C- …12 |
| 12a. | Thallus granular or sorediate, consisting of unconsolidated goniocysts (apothecia creamy whitish (or reddish brown in M. myriocarpa) …13 |
| 13a. | Thallus intense yellow-green; goniocysts 16-28 µ wide, stacked up into somewhat coralloid masses; spores 9-14.5 × 3.5-4.5 µ; very common in cool coastal regions, rare in inland BC …Micarea cf. xanthonica |
| 13b. | Thallus yellowish or bluish green; goniocysts 12-40 µ wide, heaped haphazardly; spores 8-14 × 2.5-5 µ; widespread but uncommon …Micarea micrococca |
| 12b. | Thallus smooth and continuous, or immersed, lacking goniocysts; apothecia medium reddish brown, grey, or black …14 |
| 14a. | Hypothecium light grey, K+ greenish; hymenium not pigmented; apothecia resembling those of M. peliocarpa, flattish, mottled grey and creamy white; spores 9-14 × 3-4 µ; one collection, inland BC …Micarea grisea |
| 14b. | Hypothecium colourless, K-; hymenium pigmented brown or orange-brown in upper parts; apothecia medium brown, distinctly convex or globose; spores 7-9.5 × 3-3.5 µ; known from one collection …Micarea bicolor |
Micarea alabastrites (Nyl.) Coppins
Thallus of small granules or high convex areoles 40-140 µ wide, pale green or greyish white, matte or slightly glossy, containing trebouxioid algae; apothecia usually densely crowded, 0.2-0.7 mm wide, low- to high-convex, sometimes becoming tuberculate, creamy whitish, often with a thin, receding, paler rim; hymenium 45-55 µ high, colourless or pale yellowish in upper portions; hypothecium colourless; spores 3-septate (rarely 5- or 7-septate); pycnidia usually present and abundant, pale, not stalked.
Reactions: Thallus and apothecia C+ pink.
Contents: Gyrophoric acid.
Habitat: On conifer bark in waterfall spray-zone at middle elevation.
Similar Species: Micarea peliocarpa is more common, paler apothecia and a smaller average spore size. Shade forms of this species may appear very similar, but the apothecia are usually smaller, and tend to be scattered or in small clusters rather than densely crowded.
Specimens: Micarea 8954.
Local Status: Rare.
Micarea bicolor Björk ined.
Thallus immersed, or surficial in part and then a thin, green film, containing trebouxioid algae; apothecia 0.2-0.4 mm wide, medium pinkish brown, with a paler rim that recedes with age, old apothecia uniformly light tan; hymenium 30-40 µ high, containing abundant POL+ whitish crystals, light brown in upper portions, the pigment partly clearing in K, but not changing colour; hypothecium colourless; some paraphyses with light brown pigment in the walls in upper portions, this pigment in addition to the diffuse light brown pigment in the surrounding gel; spores 7-9.5 × 3-3.5 µ, simple, narrowly ovate; pycnidia not seen.
Reactions: Spot tests all negative, though the POL+ whitish crystals in the hymenium suggest gyrophoric acid, which appears C- when in low concentrations.
Contents: Unknown, but the apothecia probably containing gyrophoric acid.
Habitat: On conifer wood in humid forest. Lower elevations.
Similar Species: Pallid forms of Micarea denigrata may look similar, but have a grey, K+ mauve pigment in the upper hymenium, and do not regularly produce a pale rim.
Specimens: Björk 12355.
Local Status: Rare.
Notes: Known only from the study area.
Micarea denigrata (Fr.) Hedl.
Thallus white to grey, brown or green, waxy or (less often) glossy, of areoles 0.1-0.25 mm wide, not appearing translucent when wet, containing a micareoid alga; apothecia without a rim or with a very thin, inconspicuous rim, usually black, sometimes grey or brown in deeply shaded sites, 0.15-0.5 mm wide; Upper hymenium usually brownish grey, K+ mauve (Note: this reaction is easily missed in less pigmented apothecia. Watch as the K wash flushes by; the mauve colour is most apparent in contrast to the pre-K pigment); spores narrowly oblong or elliptical, (0‑) 1-septate, usually with one cell larger, (7‑) 9-16 (‑18) × 2-3.3 (‑3.5) µ.
Reactions: Generally C+ pinkish red (rapidly fading).
Contents: Gyrophoric acid usually present in the apothecia.
Habitat: Mostly on wood, less often rough bark, usually within the winter snowpack. All forested elevations.
Similar Species: Pale-apotheciate forms may appear like Bacidia, most species of which are either on smooth bark, or grow above the winter snowpack, or have reddish-brown or orangish brown apothecia.
Specimens: Björk 12238, 14382; Goward 96-586.
Local Status: Common.
References: Coppins (1983).
Notes: A highly variable species that is best distinguished from other local members of genus by the presence of distinct areoles.
Micarea grisea Björk ined.
Thallus smooth or verruculose or with a few areoles around the margins, light to medium greyish green, containing a trebouxioid alga; apothecia 0.15-0.3 (‑0.4) mm wide, with a thin, distinct, persistent pale grey rim, paler than the disc, becoming undulate in outline, the disc medium grey, flat to low-convex; hymenium 35-45 µ high, POL-, colourless above, but light grey in lower portions, the grey pigment K+ greenish; hypothecium colourless; spores 9-14 × 3-4 µ, simple and 1-septate spores intermixed; pycnidia not seen.
Reactions: All spot tests negative.
Contents: Unknown.
Habitat: On wood of conifer log in humid habitat. Lower elevations.
Similar Species: Micarea cinerea and M. peliocarpa may look similar macroscopically, but have longer spores with at least 3 septae.
Specimens: Björk 13186.
Local Status: Rare.
Notes: Known only from the study area.
Micarea melaena (Nyl.) Hedl.
Thallus areolate, verruculose or granular, seldom smooth, pale tan, pale greyish green or dark grey-green, containing a micareoid alga; apothecia 0.12-0.4 (‑0.5) mm wide, jet black, matte or slightly glossy, lacking a rim, high-convex or spherical, sometimes botryoid; hymenium 30-40 µ high, streaky medium to dark blue-green or greyish blue, often darker upward K- or K+ greener; hypothecium opaque, dark purple-brown, K- or K+ more purple; spores 3-septate, 12-21 × 4-5 µ; pycnidia rare.
Reactions: C- or + pink.
Contents: ± gyrophoric acid.
Habitat: On wood of conifer snags and logs in humid forests, lower to middle elevations.
Similar Species: Biatora globulosa, which often grows in similar habitat, may appear similar and have similar hymenial pigmentation, but has a colourless hypothecium and simple or 1-septate spores.
Specimens: Goward 96-651a.
Local Status: Uncommon.
Micarea micrococca (Körb.) Gams ex Coppins
Thallus minutely granular, the granules continuous or scattered, 12-40 µ wide; apothecia 0.1-0.4 mm wide, without a rim, the disc pale to dark grey, high-convex to subspherical; hymenium 25-45 µ high, colourless or greenish-gray in upper portions, any pigment K+ mauve; hypothecium colourless; spores 8-14 × 2.5-5 µ, simple or 1-septate; pycnidia often present, immersed or surficial, white to grey, 30-120 µ wide; mesoconidia 3.5-4.5 × 1.2-1.7 µ, microconidia 5.5-8 × 0.7-1 µ.
Reactions: All spot tests negative.
Contents: methoxymicareic acid.
Habitat: On bark or wood, in humid microhabitats, usually within the winter snowpack. All forested elevations.
Similar Species: Micarea prasina is very similar, differing primarily in chemistry. A definitive identification may not be possible without TLC.
Specimens: Goward 94-866.
Local Status: Unknown.
Micarea peliocarpa (Anzi) Coppins & R. Sant.
Thallus immersed, or more often, areolate, verruculose or granular, greenish white or pale grey, occasionally dark grey, containing a micareoid alga; apothecia 0.15-0.4 (‑0.6) mm wide, usually scattered or in small clusters, pale grey or blackish, rarely slightly brownish, with a thin, slowly receding, paler rim; hymenium 40-55 µ high, olive green, bluish or grey in the upper half, colourless below, K-; hypothecium colourless; spores 3-septate, 15-23 × 3-5 µ, clavate-fusiform or elliptic-fusiform; pycnidia frequent, but inconspicuous, whitish, up to 0.2 mm wide; macroconidia 21-40 × 1-1.5 µ, septate, curved or sigmoid; microconidia 6-7 × 0.4-0.7 µ, simple, narrowly elliptical.
Reactions: Thallus and apothecia C+ pink (at least in section, LM)
Contents: Gyrophoric acid.
Habitat: On conifer twigs (especially Thuja and Tsuga) in humid forest, often growing with Lobaria. Lower elevations.
Similar Species: See notes under Micarea alabastrites and M. grisea.
Local Status: Occasional.
Micarea prasina Fr.
Thallus grey-green, bluish-green or dark pure green, appearing translucent when wet, formed of easily separated goniocysts in tight clusters to 100 µ wide, or (rarely) immersed; photocells micareoid (3-7 µ wide, deeper green than Trebouxia, at least when fresh, usually of odd polygonal shapes as opposed to globose; apothecia whitish, pale grey, brownish-gray, or charcoal grey, almost always strongly convex, usually globose and becoming botryoid (lumpy); upper hymenium colourless to light grey or olive, any pigments reacting K+ mauve; spores 0-1 (‑3) septate, usually with one cell larger, 8-14 (‑17) × 2.3-4 µ.
Reactions: C+ pink (often weakly so).
Contents: Gyrophoric acid.
Habitat: On soft, decayed wood, seldom on rough bark, always within the winter snowpack, lower to middle elevations.
Similar Species: See notes under Micarea micrococca.
Specimens: Björk 12299; Goward 03-328.
Local Status: Common.
References: Coppins (1983).
Notes: A highly variable species.
Micarea silvae-veteris Spribille ined.
Thallus areolate, granular or, mostly, verruculose, medium olive green, containing micareoid algae; apothecia often absent, 0.1-0.2 mm wide, sometimes botryoid, and then up to 0.35 mm wide, lacking a rim, constricted to the base, light to medium (sometimes dark) brown or greyish brown or blackish brown; hymenium pale to light grey-brown or olive-brown, especially in lower portions, K+ mauve, C+ mauve; hypothecium colourless or light grey- or olive-brown; 1- and 3-septate spores intermixed, (10.5‑) 14-17 × 2-2.5 µ; stalked black pycnidia common and abundant, tipped in a white conidial mass, the pycnidial wall K+ mauve (LM); mesoconidia 3.5-4 × 1.3-1.5 µ.
Reactions: All spot tests negative.
Contents: Unknown.
Habitat: On rough bark, less often wood, in humid, oldgrowth forests. Lower elevations.
Similar Species: Micarea botryoides, which is rarer in inland BC, may be found in the study area; it appears similar, but has mesoconidia of a longer length/width ratio, the pycnidial wall is K- or K+ greenish, and has black apothecia with a darkly pigmented hypothecium.
Specimens: Goward 01-210, 01-211.
Local Status: Uncommon.
Micarea cf. xanthonica
Thallus often extensive, granular, formed of goniocysts 16-28 µ wide, that often adhere into granules up to 50 µ wide, these sometimes piling up into coralloid masses, creamy yellow-green, containing a micareoid alga; apothecia matte or slightly waxy, whitish tan, 0.3-0.6 mm wide, often with attenuating “sticky” margins, rimless or with an obscure when young, low convex, or sometimes becoming high-convex or botryoid; hymenium 40-50 µ high, colourless; hypothecium colourless; spores oblong-ovoid, elliptical or oblong, 9-14.5 × 3.5-4.5 µ, mostly 1-septate, but some 3-septate; pycnidia unknown.
Reactions: All parts C-.
Contents: Unknown.
Habitat: On soft, punky wood of snags and logs, in very humid forest, less often on bark or mosses on the ground or over trunks. Lower elevations.
Similar Species: See notes under Halecania viridescens.
Local Status: Rare.