The
thallus of
Biatora toensbergii is , meaning it spreads outwards and can reach up to in diameter. It has a cracked, appearance, resembling a network of small cracks, with the individual (crust-like sections) measuring between 0.2 and 0.6 mm across. These areoles are generally flat or have an irregularly wrinkled surface. The coloration of the thallus ranges from white to light or medium gray, and it can occasionally have a greenish or brownish tint. The surface is typically matte. In a cross-section, the thallus has a height of 70–130
μm, though it can occasionally reach up to 300 μm. Notably,
Biatora toensbergii lacks a
medulla, which is the inner layer found in many lichens. The , which houses the symbiotic algae (specifically of the type), is 60–100 μm high, but can sometimes extend to 270 μm. The cortical layer, the outermost layer, is colorless and often includes bark fragments, measuring 5–35 μm in thickness. The reproductive structures, known as
apothecia, are rounded or irregularly shaped and can appear either singly or in groups. They are , meaning they sit directly on the without a stalk, and have a constricted base. The average diameter of the apothecia is 0.40–0.65 mm, but they can reach up to 1.15 mm if tuberculate (having small, wart-like projections). The of the apothecia is typically orange to red-brown, rarely light
ochre, and is weakly to moderately convex, lacking a powdery coating (). The margin of the apothecia is lighter in color than the disc and becomes less prominent over time. Internally, the (the outer tissue layer surrounding the apothecium) is colorless to yellowish or orange-brown, especially near the
hymenium (the fertile, spore-bearing tissue). The exciple is composed of radiating, weakly branched and anastomosing (interconnecting)
hyphae. The , located below the hymenium, is 35–150 μm high and is colorless to pale orange-brown, often with a pinkish hue. The , directly beneath the hymenium, is 30–65 μm high and slightly darker than the hypothecium. The hymenium itself is 45–60 μm high and colorless. The
paraphyses, which are sterile filaments among the
asci (spore-producing cells), are simple or weakly branched. The asci of
Biatora toensbergii are of the
Biatora type, containing 8 spores and measuring 30–44 μm by 8–11 μm. The
ascospores are colourless, (occasionally with one to three
septa), and measure 10.0–16.4 μm by 3.5–4.7 μm, with a (outer spore wall) about 0.5 μm thick. Chemical
spot tests on the thallus reveal it is negative for C and K, but positive for P (paraphenylenediamine), which turns orange-red.
Thin-layer chromatography identifies the presence of
argopsin and traces of
norargopsin in its chemical composition. , which are asexual reproductive structures, have not been observed in North American specimens. ==Habitat and distribution==