Sheepish Pelt Lichen

Description

Sheepish Pelt Lichen is a recently recognized lichen. It occurs in Europe and North America. In the United States it occurs from Maine to Connecticut, west to Minnesota, and in the Pacific Northwest. It occurs across southern Canada, north in the west to Alaska. The species is likely more common than the limited number of records indicate because it was only recently recognized as distinct from Peltigera didactyla in 2018.

The ecology of Sheepish Pelt Lichen is still little studied due to its recent recognition as a separate species. Like Peltigera didactyla, it is found in moist and shaded habitats, in or at the margins of forests, and in disturbed habitats. It grows on the ground on soil, among mosses that grow on soil (tericolous), and on plant debris.

The vegetative body (thallus) is leaf-like (foliose). It forms a rosette that is often up to 2″ (5 cm) in diameter, sometimes up to 3″ (8 cm) in diameter. The lobes are elongate and flat or concave, and the tips are rounded to almost straight across (subtruncate). They are usually 5⁄16″ to ⅜″ (8 to 10 mm) wide, and up to 1¼″ (3 cm) long, sometimes larger, up to ⅝″ (15 mm) wide and up to 2″ (5 cm) long.

The upper surface is gray to pale brown and dull when dry, blackish green when wet. It is densely covered with short, matted, whitish-gray hairs (tomentose), especially toward the margins and on younger parts. The protective outer layer (cortex) is pseudoparenchymatous—it is composed of fungal threads (hyphae) so tightly packed that they resemble the three-dimensional cells of other organisms, though they are not truly cellular.

Granular, asexual, reproductive structures (soredia) are produced in persistent, orb-shaped, up to 1⁄16″ (2 mm) wide structures (soralia). They appear as pale patches on the upper surface of the lobe, clustered in a submarginal band.

The lower surface is white with a network of pale veins, and white, 3⁄16″ (5 mm) long, densely branched, root-like structures (rhizines) that become darker toward the middle. It does not have an outer protective layer (cortex).

Sexual (spore-producing) reproductive structures (apothecia) are rare. When present, they are reddish brown, saddle-shaped, and up to 3⁄16″ (5 mm) wide, and they appear on short, ascending lobes.

Unlike Peltigera didactyla, from which it was separated, Sheepish Pelt Lichen reacts to applied chemicals, though the reaction is faint and it disappears quickly.

Similar Species

Ecology

Substrate

Ground

Growth Form

Foliose

Habitat

Forests and forest edges, in moist and/or shaded areas

Hosts