Leptorhaphis
Unlichenized fungi that are often part of crust lichen communities; thallus non-algal, forming a white stain in the substrate, or not at all apparent; perithecia black, flat to hemispheric, with dark brown pigments in the wall; hymenium usually IKI+ orange, formed of few, densely branched and anastomosing paraphysis-like hyphae of short cells; asci broadly clavate, rather thin-walled, without a distinct tholus, IKI-; spores 8 per ascus, twisted into one or two bundles, fusiform to acicular, often curved, with 1-3 transverse septae.
References: Harris 1973.
| 1a. | Perithecia flat or scarcely raised above the substrate, spores tapering to fine points at the ends, 20-28 × 2-4 µ; paraphyses tangled, difficult to observe individually in water mount; growing on Betula bark …Leptorhaphis epidermidis |
| 1b. | Perithecia domed; spores blunt at the ends, often with more than 1 septum, 11-27 × 2-3.2 µ; paraphyses, more or less straight, easily observed in water mount; perithecia hemispheric, round, surficial; growing on Populus tremuloides bark …Leptorhaphis hemisphaerica |
Leptorhaphis epidermidis (Ach.) Th. Fr.
Thallus immersed, lacking algae, invisible except immediately around the perithecia; perithecia low-convex (almost flat), tending to be elongated parallel to the stretch of the Betula bark, 0.25-0.4 mm wide, brownish black; perithecial wall dark brown as seen in LM, the exciple colourless and inconspicuous; paraphyses obscure, difficult to observe; asci clavate, 40-70 × 10-16 µ, IKI-; spores twisted in one or two bundles in the ascus, curved-fusiform with bluntly pointed ends, colourless, with a single central crosswall, the cells of equal size, 24-65 × 2.5-4 µ.
Reactions: Hymenium I- or I+ yellowish.
Contents: No known lichen substances.
Habitat: Smooth bark surfaces on trunks of Betula papyrifera. Lower elevations.
Similar Species: No other peritheciate lichen or crust fungus in our study area grows on bark of Betula trunks and produces such long, narrow spores.
Specimens: Björk 12257, 12852; Goward 93-10.
Local Status: Common.
Leptorhaphis hemisphaerica Björk ined.
Thallus partially surficial but very thin, smooth, containing a few lichenized trebouxioid algae; perithecia high convex to subspherical, round in outline, matte jet black, 0.08-0.2 mm wide; perithecial wall dark greyish brown as seen in LM, the exciple colourless and inconspicuous; hymenium densely packed with tiny oil droplets, the lower half and the hypothecium K+ light purple-violet; paraphyses easily observed, branched and anastomosed from about the midpoint upwards, about 1 µ wide throughout; asci elliptical, widest near the middle, IKI-, 30-38 × 9-12 µ; spores worm-shaped, not much curved, colourless, with 0-3 septae, the cells of equal size, 11-27 × 2-3.2 µ.
Reactions: Thallus spot tests all negative.
Contents: Unknown, but probably lacking known lichen substances.
Habitat: Smooth bark around branch scar of medium-age Populus tremuloides. Lower elevations.
Similar Species: No other peritheciate lichen in our area has tiny, high-convex perithecia and colourless, worm-shaped spores.
Specimens: Björk 13781.
Local Status: Rare.
Notes: Known only from inland BC.