Verrucaria
Crustose lichens containing a trebouxioid alga; thallus immersed, smooth, cracked, areolate, verrucose, granular, subsquamulose or lobate, some species parasitic; perithecia black or dark brown, variously immersed, partly sunken or surficial, the exciple pigmented or not, often with an outer wall layer; hymenium colourless, formed of mostly simple paraphysis-like hyphae that may partly dissolve into gel with maturity; asci clavate, thin-walled, IKI-; spores 8 per ascus, broadly elliptical, elliptical, or ovate.
References: Breuss 2007.
| 1a. | Thallus waxy, olive-green, very thin and film-like, of flat areoles or verruculose; perithecia 0.1-0.2 mm wide; spores 13-18 × 6-7.5 µ; known from only one collection from tip-up roots …Verrucaria micareoides ined. |
| 1b. | Thallus distinctly brown, grey-brown or green-brown, matte, of convex areoles, or verrucose or cracked; perithecia mostly wider than in 1a; spores various, but mostly larger than in 1a …2 |
| 2a. | Exposed portion of the perithecia 0.1-0.2 mm wide, sunken about 3/4 into the thallus, spores 15.5-23 × 7-10 µ, averaging 18.5 × 7 µ; thallus cracked …Verrucaria canadensis ined. |
| 2b. | Exposed portion of the perithecia 0.2-0.3 mm wide, sunken or not, spores at least 19 µ long, average length at least 21 µ; thallus cracked or not …3 |
| 3a. | Perithecia deeply sunken in the thallus, the apex flush with the thallus; 0.2-0.35 mm thick, cracked-areolate, the areoles smooth, dark brown; spores 29-32 × 8-11 µ; one collection, central BC …Verrucaria fissurina ined. |
| 3b. | Perithecia with the apex distinctly raised above the thallus; thallus up to 0.15 mm thick, cracked or not, but if cracked-areolate, then the areoles distinctly verrucose; spores up to 28 µ long …4 |
| 4a. | Thallus not cracked or with scattered irregular cracks, grey-brown; spores 26-28 × 13-15 µ; perithecial wall dark pinkish brown, K+ grey-brown …Verrucaria pausiaca ined. |
| 4b. | Thallus with a regular pattern of cracks, dark brown; spores 19-24 × 8-9.5 µ; perithecial wall brownish black, K-; two collections, central BC …Verrucaria intricatula ined. |
Verrucaria canadensis Björk ined.
Thallus continuous over areas of 3-15 mm, cracked, moderately thick, light olive-gray; perithecia 0.2-0.3 mm wide, about 3/4 sunken in the thallus, only the area around the ostiole exposed, this blackish grey-brown; perithecial wall 25-30 µ thick, opaque dark brown, curling in downwardly below the hypothecium, but with a gap at the bottom, also spreading outward through the thallus a short distance; paraphyses disintegrating into gel; periphyses 8-13 µ long, abundant throughout the perithecial ceiling, not just around the ostiole; spores elliptical to elliptic-ovate, colourless, 15.5-23 × 7-10 µ.
Reactions: Spot tests all negative.
Contents: Unknown.
Habitat: On hard-weathered wood of a Thuja root exposed on river cut-banks at lower elevation.
Similar Species: A very similar, undescribed, coastal species on driftwood in estuaries differs in having the perithecial wall complete below the hypothecium.
Specimens: Björk 10844.
Local Status: Rare.
Notes: Known only from coastal and inland BC, always on wood of river-side roots and driftlogs.
Verrucaria fissurina Björk ined.
Thallus margined by a narrow black prothallus, thick, cracked-areolate and somewhat lobed around the margins, the areoles 0.2-0.3 mm wide; perithecia 0.3-0.45 mm wide, about 2/3 sunken in the thallus, the exposed part jet black; perithecial wall 40-55 µ thick; paraphyses dense, but disintegrating into gel; periphyses not observed; spores light gold-brown at maturity, elliptical to elliptic-ovate; 29-31 × 8-11 µ.
Reactions: Spot tests all negative.
Contents: Unknown.
Habitat: On hard, weathered wood on exposed roots on a river cut bank. Lower elevations.
Similar Species: The only other lobed Verrucaria in our area is V. kootenaica, but that species is olive-gray and much more distinctly lobed (Phaeophyscia-like). Staurothele is lobed around the thallus margins also, and is similarly coloured, but is bullate and has algal cells in the hymenium.
Specimens: Björk 12218.
Local Status: Rare.
Notes: Known only from a single collection from the Clearwater River. This may be a normally saxicolous species, but no similar rock-dwelling species is known from our study area.
Verrucaria intricatula Björk ined.
Thallus spreading over as much as 5 cm, intricately cracked-areolate, verruculose, the areoles with 3-7 tiny verrucae, dark olive; perithecia about 2/3 sunken in the thallus; the perithecial wall in dark brown two layers, both of which reach a bit more than half way down the perithecial chamber, the outer one spreading outward slightly; paraphyses disintegrated into gel; periphyses about 10 µ, positioned throughout the perithecial ceiling; spores colourless or light gold-brown, 19-24 × 8-9.5 µ.
Reactions: Spot tests all negative.
Contents: Unknown.
Habitat: On decaying, peeling bark on decaying Betula trunk on river shore at lower elevation.
Similar Species: Unlike any other species in the study area.
Specimens: Björk 12347.
Local Status: Rare.
Notes: Known only from a single collection along the Clearwater River.
Verrucaria micareoides Björk & Wheeler ined.
Thallus patchy, only a few mm across, areolate or verruculose, medium olive green, inconspicuous; perithecia 0.1-0.2 wide, hemispheric, not sunken in the thallus, without a thalline cover; dark greyish brown, the wall 0.15-0.2 µ wide, dark brown, not extending below the hypothecium; paraphyses disintegrating into gel; periphyses about 5-8 µ long, positioned only near the ostiole; spores 13-18 × 6-7.5 µ, elliptical, pale brownish at overmaturity.
Reactions: All spot tests negative.
Contents: Unknown.
Habitat: On bark of tip-up roots in swamp forests. Lower elevations.
Similar Species: At first glance similar to some Micarea species. Thrombium epigaeum, a normally terricolous species that sometimes grow on tip-up mounds, has an extensive thallus with a fibrous, light olive brown thallus and perithecia more deeply sunken in the thallus.
Specimens: Tim Wheeler s.n. 15 October, 2006 (UBC).
Local Status: Rare.
Notes: Known from only a single collection in the study area.
Verrucaria pausiaca Björk ined.
Thallus areolate, the rounded areoles 0.1-0.25 mm wide, adnate or lifting slightly at the margins, moderately thick, patchily covering areas up to 20 cm wide, olive, waxy, with a few cracks in denser patches; perithecia about 1/2 sunken in the thallus at maturity; perithecial wall 40-50 µ thick, dark pinkish brown, K+ greyish, in two layers, the outer layer separating from the inner about half way down, extending only very slightly into the thallus, the inner layer complete below the hypothecium; spores 26-28 × 13-15 µ, colourless, elliptical.
Reactions: Spot tests all negative.
Contents: Unknown.
Habitat: On hard-weathered wood of Thuja roots on river cut-banks. Lower elevations.
Similar Species: The rounded areoles are distinctive among epiphytic Verrucaria in BC. The saxicolous Verrucaria of BC are too poorly known to know which may appear similar.
Specimens: Björk 12223.
Local Status: Rare.
Notes: Known only from a single collection along the Clearwater River.