Dog Pelt Lichen

Description

Dog Pelt Lichen is a common and widespread lichen. It occurs in Europe, Asia, North America, and South America. It occurs throughout most of the United States and Canada, but it is absent from the Great Plains and the Great Basin. It is common but not abundant throughout its range—there are many occurrences, but only scattered individuals in a population. It grows in open or shaded forests, on soil, mosses, rotting wood, and sometimes at the bases of tree trunks. It also grows in fields and in sandy areas under full sun.

The vegetative body (thallus) is leaf-like (foliose) and forms a rosette up to 8″ (20 cm) in diameter. When it first appears, it grows with a roughly circular form. As it ages it disintegrates into irregular groups of elongated flattened lobes. The lobes are relatively thick, ⅝″ to 1¼″ (15 to 30 mm) wide, up to 4″ (10 cm) long. The tips are rounded, and the margins are downturned and entire, not forked.

The upper surface is not ridged. It is covered with cobweb-like hairs, especially along the margins. When wet it is blackish-green, transparent, and often whitish at the edges. When dry it is gray or brownish gray to gray and opaque. It is composed not of three-dimensional cells but of fungal threads (hyphae) that are so tightly packed that the individual threads are not discernible in cross section (pseudoparenchymatous).

The lower surface is whitish with distinct raised veins. The veins are brownish in the center and whitish at the margins. It is attached to the substrate by whitish, brush-like, up to ⅛″ (4 mm) long, root-like structures (rhizines). It does not have an outer protective layer (cortex).

Sexual (spore-producing) reproductive structures (apothecia) on the margins of the thallus are frequent. The apothecia are ⅛″ to ⅜″ (4 to 10 mm) wide, oblong to more or less round, and curved inward, appearing saddle shaped. The disc is flat, smooth, and dark brown to black.

To help identify lichens, specialists perform spot tests by applying a drop of common chemical reagents to the surface. Many lichens show a distinctive color change—their unique “chemical fingerprint.” However, the Dog Pelt Lichen does not react to any of the standard tests, including the crucial P-test, meaning it shows no color change when the chemicals are applied.

Similar Species

Ecology

Substrate

Ground

Growth Form

Foliose

Habitat

Open or shaded forests, fields, and sandy areas

Hosts