Caloplaca
Crustose, microfoliose or microfruticose lichens with a trebouxioid alga; thallus smooth, areolate, placodioid, verruculose, sorediate, leprose, isidiate, microfoliose or microfruticose; colour ranging through orange, yellow, red, grey, brown, white or green; thallus in some species immersed and not apparent; some species parasitic on other lichens; apothecia of most species with both an algal rim that often resembles the thallus in colour and texture, as well as with an inner, excipuloid rim that may also contain algae and which may be alike or dissimilar from the outer rim, sometimes only the inner rim present; disc generally orange or red-orange, pigmented with anthraquinones, but these lacking in some species having brown or black apothecia, often also pruinose with additional pigments in crystal form; excipuloid rim of rounded cells or cylindrical hyphae embedded in gel, with or without an algal layer; hymenium formed of mostly straight paraphyses embedded in gel, the paraphysis tips generally swollen, and usually surrounded by anthraquinone crystals; hypothecium colourless in almost all species; asci clavate, IKI+ blue, with darker blue inner and outer domes in the well-thickened tholus; spores usually 8 per ascus, polarilocular (with an unevenly thickened, septum-like division that is usually much thicker than the outer walls such that the cell lumina are pushed away from each other toward the spore ends), some species with spores having 4 cell lumina.
Note: Some species currently placed in Caloplaca appear to have arisen through a process of reduction from the foliose genus Xanthoria. Even Xanthoria polycarpa can occasionally produce solitary apothecia in the absence of a leafy thallus. Such thalli resemble Caloplaca holocarpa, but have more highly contrastive apothecia, the disc being a deeper orange than the rim. They also usually grow near normally developed thalli of X. polycarpa.
References: Clauzade & Roux 1985; Søchting 1994; Goward et al. 1996; Søchting & Tønsberg 1997; Foucard 2001; Wetmore 1994, 2004, 2007; Spribille 2006.
| 1a. | Thallus sorediate; apothecia often absent …2 |
| 2a. | Soredia grey, brownish grey, olive grey, bluish or white, K- or K+ mauve (reactions visible only in LM) …3 |
| 3a. | Soredia whitish, produced in round soralia with a raised, continuous brownish grey or purple rim; growing on relatively acidic bark, especially on shrubs at upper forested elevations …Caloplaca sorocarpa |
| 3b. | Soredia grey or bluish, produced in irregularly shaped soralia without a rim, or with an irregular, interrupted rim; on base-rich bark at lower elevations …4 |
| 4a. | Soredia grey or brownish grey, lacking bluish tones, K-; soralia concave, about 0.3 mm wide; apothecia grey-brown, K-; rare …Caloplaca obscurella |
| 4b. | Soredia dark bluish grey, K+ mauve as seen in LM; soralia convex, 0.1-0.25 mm wide; apothecia bright orange, K+ instant dark red-purple; common, but easily overlooked …Caloplaca ahtii |
| 2b. | Soredia yellow or orange, K+ dark red-purple (reaction visible macroscopically) …5 |
| 5a. | Soredia one layer thick throughout, brilliant canary-yellow; to be sought on firm bark of old Populus trichocarpa trunks …[Caloplaca xanthostigmoidea (Räsänen) Zahlbr. form 1] |
| 5b. | Soredia more than one layer thick throughout most of the thallus, duller colours, not brilliant yellow …6 |
| 6a. | Soredia in coralloid mounds, orangish green, emerging from patches of crust 1.5-2.5 mm wide; to be sought on conifer branches and twigs in waterfall sprayzones …[Caloplaca xanthostigmoidea (Räsänen) Zahlbr. form 2] |
| 6b. | Soredia fine or granular, not or scarcely coralloid, colour various, emerging haphazardly from an immersed crust or intermixed with patches of crust up to 0.5 mm wide …7 |
| 7a. | Soredia granular, evenly dispersed over an immersed thallus, pale greenish orange to yellow-orange, never white; hypothallus lacking; to be sought, e.g., on conifer trunks and branches in rainforests …[Caloplaca xanthostigmoidea (Räsänen) Zahlbr. form 3] |
| 7b. | Soredia granular to very fine, mostly haphazardly heaped, older soredia mostly white, surficial soredia of various colours, greyish, yellow, pale orange, green and white, colours often intermixed; white hypothallus generally present; common and widespread, in dry to wet forest habitats …Caloplaca xanthostigmoidea form 4 |
| 1b. | Thallus lacking soredia; apothecia ever-present …8 |
| 8a. | Apothecial rim and disc dark rusty red-brown, appearing blackish as seen from a distance …9 |
| 9a. | Hymenium 65-70 µ high; upper hymenium K+ pink-rose, reaction not turning violet-purple; spores 10-16 × 6-8 µ …Caloplaca cf. oleicola |
| 9b. | Hymenium 85-115 µ high; upper hymenium K+ red-purple turning violet-purple; spores 12.5-18 × 5.5-10 µ …Caloplaca atrosanguinea |
| 8b. | Apothecial disc (and often also the rim) bright orange, red, or rusty red, not appearing at all blackish …10 |
| 10a. | Apothecia with the rim grey or white throughout and no orange inner rim visible between the rim and disc …11 |
| 11a. | Rim white; disc yellow; granules of the upper hymenium reacting K+ pink-rose (LM); spores 15-17 × 7.5-8.5 µ; occasional, usuualy on aspen, willow or cottonwood bark, rarely on rock (limestone) …Caloplaca albogilva ined. |
| 11b. | Rim grey; disc orange; granules of the upper hymenium reacting K+ red-purple (LM); spores 10-15 × 6-8.5 µ; habitat various, on bark, detritus, moss and rock …Caloplaca cerina |
| 10b. | Apothecia with an orange or yellow inner and/or outer rim, sometimes with additional greyish thalline material on the exterior of the outer rim …12 |
| 12a. | Thallus K+ instant red-purple, formed of yellow-orange areoles, K+ instant red-purple; spores 15-18 × 6-10 µ; uncommon, on nutrient-rich bark …Caloplaca flavorubescens |
| 12b. | Thallus K-, green, grey, brownish or whitish, areoles lacking, or present but of dull colours (note, C. holocarpa often produces apothecial initials that resemble areoles); spores and habitat various …13 |
| 13a. | Spores with the cells much longer than the width of the septum, septum 1-3 µ wide (check mature, not overmature spores) …14 |
| 14a. | Apothecia orange, 0.5-1.5 mm wide, mostly in dense, large clusters; spores 15-22 × 7-10 µ; mostly on moss, occasional on bark or wood …Caloplaca jungermanniae |
| 14b. | Apothecia deep blood red to brick red, 0.2-0.3 mm wide, mostly solitary or in small clusters; spores 11-13 × 3-4 µ; usually on rock, occasional on wood …Caloplaca athroocarpa |
| 13b. | Spores with the cells about equal to or much shorter than the width of the septum, septum 3-7 µ wide …15 |
| 15a. | Apothecia brownish red or brick-red, with at least some brownish tone, at least when fully mature …16 |
| 16a. | Apothecia C-; spores 11-17 × 5-9 µ, the septum 3-5 µ wide; mostly on moss, occasional on wood or bark …Caloplaca ammiospila |
| 16b. | Apothecia C+ dark red-purple; spores 12.5-17 × 8-11.5 µ, the septum 4-7 µ wide; on bark or rarely wood …Caloplaca cf. ferruginea |
| 15b. | Apothecia pure orange or yellow-orange, lacking any brownish tone …17 |
| 17a. | Apothecia with at most sparse algae in the rim, but sometimes with thalline granules clinging to the outside of the rim; thallus with blue-gray or green-gray soredia in inconspicuous concave soralia; spores 10.5-13 × 5-7 µ …Caloplaca ahtii |
| 17b. | Apothecia with abundant algae in the rim, thalline material on the outside of the rim mostly smooth, not granular; soralia lacking; spores 10-14 × 5-9 µ; a highly variable species, probably encompassing more than one taxon in our area …Caloplaca holocarpa |
Caloplaca ahtii Søchting
Thallus inconspicuous, except for the soralia, which are usually tiny mounds of soredia, the soredia 15-30 µ wide, grey-green or bluish grey, with a bluish grey pigment in the walls of the surrounding hyphae (LM); apothecia up to 4 (‑5) mm across, sparsely scattered, bright yellowish orange, often with grey-green soredia clinging to the rim, which is thick and persistent and coloured like the disc or slightly darker, and which either lacks algal cells or contains only sparse algae; spores 10.5-13 × 5-7 µ.
Reactions: The greyish pigment on the soredia reacts K+ mauve (LM), and the apothecia react K+ instant red-purple.
Contents: Anthraquinones in the apothecia, unknown pigment in the soredia.
Habitat: On nutrient-rich bark, especially Populus trichocarpa and fissured bark of old Populus tremuloides. Lower to middle elevations.
Similar Species: In Caloplaca holocarpa, the apothecial rim lacks soredia and bears copious algal cells. By contrast, the apothecial rim of C. ahtii usually bears at least some soredia, and contains few if any algal cells. The two species often grow intermixed and can be difficult to distinguish.
Specimens: Goward 96-697.
Local Status: Occasional.
Caloplaca albogilva Björk ined.
Thallus pale grey or white, areolate or smooth; Apothecia scattered or a few clustered, 0.3-1.2 mm wide, the rim prominent and persistent, covered in pure white pruina, the pruina eroding away with age, revealing a pale yellow colour beneath, the disc flat to low-convex, lemon-yellow and densely yellow-pruinose; hymenium 60-80 µ high; upper hymenium with yellow-gold granules, K+ non-bleeding rose-red; hypothecium colourless, the layer below it with abundant algae; paraphyses to 4 µ wide at the tip; spores 15-17 × 7.5-8.5 µ, the crosswall 5-6 µ thick.
Reactions: All thallus reactions K-.
Contents: Unknown, untested, but the apothecia containing anthraquinones.
Habitat: Nutrient-rich bark of Populus tremuloides, Juniperus scopulorum, and Salix. Lower to middle elevations.
Similar Species: Caloplaca cerina differs in apothecial colours, being gray and orange rather than white and yellow. Additionally, the upper hymenium turns red-purple in K in a bleeding reaction.
Specimens: Björk 15156.
Local Status: Uncommon.
Notes: This species also grows on limestone. Known only from inland BC, eastern Washington, and northern Idaho.
Caloplaca ammiospila (Wahlenb.) H. Olivier
Thallus smooth, grey, inconspicuous; apothecia matte, becoming crowded with maturity, rusty reddish orange, 0.3-0.8 mm wide, with both a thalline rim and a prominent exciple, the two rims eventually receding and the disc becoming domed; spores ellipticial, 11-17 × 5.5-8.5 µ, the septum about 3-5.5 µ wide.
Reactions: Apothecia K+ instantly red-purple.
Contents: Anthraquinones in the apothecia.
Habitat: Usually on mosses or detritus, seldom on wood. Collected once on a snag at a lake shore at middle elevation.
Similar Species: Caloplaca jungermanniae has more brightly coloured apothecia. Caloplaca cf. ferruginea has smaller apothecia and a white crust.
Specimens: Björk 9481.
Local Status: Rare as an epiphyte.
Caloplaca athroocarpa Anzi
Thallus light grey or whitish, smooth, verruculose or immersed; apothecia scattered, deep orangish red, slightly pruinose on the disc, with a thin and undulating, but prominent and persistent rim; spores narrowly elliptical, 11-13 × 3-4 µ, with a septum that is much thinner than the length of the lumina, only about 1 µ wide.
Reactions: Thallus reactions all negative, but the apothecia react K+ instantly red-purple.
Contents: Anthraquinones in the apothecia.
Habitat: Usually on rock, rarely on worked wood, also on bark in drier regions. Lower to middle elevations in our area.
Similar Species: Caloplaca fraudans (not yet documented from the study area) has a broader spore septum. It is characteristic of drier forest types. Caloplaca ferruginea can also sometimes be similar, but usually has a more conspicuous thallus. It too has a broaderr spore septum.
Specimens: Björk 11647, 17839 (under Strangospora deplinata).
Local Status: Uncommon as a saxicole, rare as an epiphyte.
Caloplaca atrosanguinea (G. Merr.) Lamb
Thallus inconspicuous, grey or green-gray; apothecia scattered, 0.35-0.7 mm wide, blackish red-brown, matte or moderately glossy, often with a reddish iridescence; exciple cortex and upper; hymenium 85-115 µ high, covered in upper portions with dark red-brown anthraquinone crystals; spores polarilocular (with a thick septum-like thickening separating the two cells, 12.5-18 × 5.5-10 µ.
Reactions: None.
Contents: Unknown anthraquinones.
Habitat: On moderately nutrient-enriched bark, rarely wood, above the winter snowpack. Low and middle (rarely high) elevations.
Similar Species: In Lopadium disciforme the apothecia are pure black, lacking in reddish tones. The spores are not at all similar, being muriform and solitary in the asci.
Specimens: Goward 01-816.
Local Status: Common.
References: Wetmore (1994).
Caloplaca cerina (Ehrh. ex Hedwig) Th. Fr.
Thallus pale to dark grey or bluish-gray or olive, continuous and smooth or verruculose, or areolate throughout, sometimes immersed; apothecia single, clustered or crowded with maturity, 0.3-0.8 mm wide (ours), the rim pale to dark grey, prominent and persistent, the disc yellow-orange or greenish orange, most remaining flat; spores 10-18 × 6-9.5 µ, the crosswall 3.5-6 µ thick.
Reactions: All thallus spot tests negative.
Contents: Anthraquinones.
Habitat: Mostly at bases of large trunks of Populus tremuloides and Salix, or bases of large Pseudotsuga trunks in dripzones. Lower to middle elevations.
Similar Species: Caloplaca pinicola and C. populicola have apothecia with blackish-gray or jet black rims. Additionally, C. pinicola usually produces soredia, and C. populicola has a well formed dark gray, areolate thallus.
Specimens: Björk 11648; Goward 01-841.
Local Status: Common.
References: Purvis et al. (1992), pp. 147-148; Foucard (2001), pg. 120.
Notes: A highly variable species; whether the local material conforms with the type of C. cerina is uncertain.
Caloplaca cf. ferruginea (Huds.) Th. Fr.
Thallus white, smooth or areolate, rather glossy, often outlined with a blackish prothallus; apothecia red-orange, 0.25-0.5 (‑0.8) mm wide; rim thin but persistent, with a very thin, papery thalline rim when young, this quickly receding, the excipular rim containing algae; spores 11-17 × 6-9 µ, with a septum about 4-7 µ thick.
Reactions: All parts of the apothecia K+ instant red-purple and C+ very dark red-purple; thallus K-, C-, KC-.
Contents: Unknown.
Habitat: On conifer twigs in a waterfall sprayzone (Dawson Falls).
Similar Species: No other Caloplaca in our area has the combination of red-orange apothecia and a white thallus. The C+ reaction of the apothecia is also unusual in Caloplaca.
Specimens: Björk 15186.
Local Status: Rare.
Notes: Typical Caloplaca ferruginea has an inconspicuous grey thallus, and somewhat larger apothecia and spores. Additionally the apothecial rim of C. ferruginea usually lacks algae, and the thallus and apothecial rim are C+ red. The form documented here is known predominantly from coastal areas; only in the study area is it currently known to occur inland.
Caloplaca flavorubescens (Hudson) J.R. Laundon
Thallus patchy-areolate, orangish yellow, with a waxy appearance, often with a whitish or bluish prothallus; apothecia single, clustered or crowded, 0.3-1 (‑3) mm wide, the rim orange or yellow-orange, prominent and persistent, the disc the same colour as the rim and usually sunken lower than it, concave to flat or sometimes low-convex; hymenium 65-80 µ high; the upper hymenium with gold granules, K+ bleeding red-purple; hypothecium colourless; paraphyses to 4 µ wide at the tips; the lower part of hymenium and hypothecium with fine oil droplets; spores 12-18 × 6-10 µ, the crosswall 5-9 µ.
Reactions: Thallus and apothecia K+ red-purple.
Contents: Thallus and apothecia containing anthraquinones.
Habitat: Drip-zones, polypores, old aspens and cottonwoods (Populus), once on an old Betula papyrifera not in a drip-zone. Lower elevations.
Similar Species: Caloplaca holocarpa usually lacks a well-developed thallus, but is otherwise similar. Juvenile apothecia of C. holocarpa often produce thallus-like mounds of orange intermixed with the apothecia.
Specimens: Björk 13676.
Local Status: Occasional.
Notes: Another highly variable species needing further study.
Caloplaca holocarpa (Hoffm. ex Ach.) A.E. Wade
Thallus medium to dark grey or olive-gray, rarely with a black hypothallus, often immersed; apothecia mostly single, a few clustered, 0.3-1 mm wide, the rim yellow orange, orange or reddish orange, prominent and persistent, the disc lower than and the same colour as the rim, concave to flat or low-convex; hymenium 60-75 µ high; upper hymenium gold-granular, K+ bleeding red-purple; hypothecium colourless, the layer below containing abundant algae paraphyses 3-6 µ wide at the tip; spores 10-14 × 5-9 µ, the crosswall 4-7 µ thick at a point half way between the outer wall and the channel.
Reactions: All thallus spot tests negative, but the apothecia K+ instant red-purple.
Contents: Anthraquinones in the apothecia.
Habitat: Any nutrified bark or wood surface above the winter snowpack. Lower to middle elevations.
Similar Species: See notes under Caloplaca flavorubescens.
Specimens: Björk 8994, 10766, 12335; Goward 94-845.
Local Status: Very common.
Notes: Extremely variable, likely representing more than one species.
Caloplaca jungermanniae (Vahl) Th. Fr.
Thallus greyish or whitish, thin, or sometimes not apparent; apothecia dull orange, matte, 0.3-1 (‑1.5) mm wide, distinctly constricted at the base, with both a thalline rim coloured like the thallus, and a well-developed exciple containing algae; spores elliptical to elliptic-fusiform; 15-22 × 7-10 µ, the septum about 3.5 µ wide.
Reactions: Apothecia K+ instant red-purple.
Contents: Anthraquinones in the apothecia.
Habitat: Usually on mosses or detritus, rarely on wood. All forested elevations.
Similar Species: See notes under Caloplaca ammiospila.
Specimens: Goward s.n. (26 June, 1978) hb. Goward.
Local Status: Uncommon as a terricole, rare as an epiphyte.
Caloplaca obscurella (Kröb.) Th. Fr.
Thallus areolate, light to medium grey or olive-gray, most areoles with a deeply concave soralium on the upper surface, these about 0.3 mm wide, producing grey or bluish grey soredia; apothecia 0.3-0.8 mm wide, matte, medium to dark brownish grey, the rim thin or thick, persistent, somewhat paler than the disc; hymenium light grey-brown in upper portions, lacking crystals; spores 10-14 × 4-8 µ, with a septum 4-8 µ wide.
Reactions: All spot tests negative.
Contents: No known lichen substances.
Habitat: On Thuja bark at a river shoreline. Lower elevations.
Similar Species: Caloplaca ulcerosa, known in northeast BC, may eventually be found in the study area; it has a thinner and often darker blue-gray thallus and, orange, K+ red-purple apothecia. Apothecia are often lacking in both of these species, leaving only the thalline characters to distinguish them.
Specimens: Björk 12331.
Local Status: Rare.
Caloplaca cf. oleicola (Steiner) van den Boom & Etayo
Thallus thin, whitish-gray, smooth, or inconspicuous; apothecia 0.25-0.5 mm wide, reddish black, with a thin but persistent excipular rim coloured like the disc and containing few algae; hymenium 65-70 µ high, topped in dark red-brown crystals; crystals in the outer layer of the exciple and the upper hymenium react K+ pink-rose; spores 10-16 × 6-8 µ, with a septum 3.5-5 µ wide.
Reactions: Spot tests all negative.
Contents: Anthraquinones in the apothecia.
Habitat: On Alnus bark in shrub thickets. Lower elevations.
Similar Species: Caloplaca atrosanguinea has larger K+ red-purple apothecia and larger spores.
Specimens: Breuss 10816 (W).
Local Status: Occasional.
Notes: The occurrence of this species in humid Alnus-Salix thickets, the mostly straight paraphyses with broader apices, and the paler internal pigmentation suggest that this may not be the same as European C. oleicola, which grows in xeric habitats in the Mediterranean.
Caloplaca sorocarpa (Vainio) Zahlbr.
Thallus smooth, grey, often expansive; soralia scattered, round and raised on a flat disc rimmed by a thin purple-brown margin, appearing apothecium-like; soredia whitish, 15-30 µ wide; apothecia (not seen in any of our abundunat material) rust red, with a thin margin, spores 12-15 × 5-8 µ, the crosswall 3-5 µ wide.
Reactions: The purple-brown margin of the soralia reacts K+ deep purple.
Contents: Roccellic acid, anthraquinones.
Habitat: Smooth bark of shrubs within the winter snowpack. Lower to (especially) upper forested elevations.
Similar Species: The evenly spaced, perfectly round soralia margined by a purple-brown ring is unlike anything else in our area.
Specimens: Goward 94-842.
Local Status: Common.
Notes: Tønsberg (1992) doesn’t note the purple-brown rim of the soralia that occurs in our material.
Caloplaca xanthostigmoidea (Räsänen) Zahlbr. Form 4
Thallus sorediate throughout, the soredia granular to very fine, heaped haphazardly, rising from a white hypothallus, older soredia turning whitish, but younger soredia variably greyish, yellow, dull orange, green or with colours intermixed; apothecia not known.
Reactions: All pigmented soredia K+ instant blood-red.
Contents: Anthraquinones.
Habitat: On mossy twigs, branches and trunks in humid forest. Lower elevations.
Similar Species: No other epiphytic sorediate crust in the study area is weakly pigmented throughout with anthraquinones.
Specimens: Björk 14391; Goward 96-1119, 96-947.
Local Status: Rare or uncommon.