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Horsehair Lichen: A Detailed Overview

Horsehair lichen refers to a variety of lichen species, particularly those within the genus Bryoria and formerly within Alectoria, characterized by their filamentous, hair-like appearance.

Considerations for Pets

• Horsehair lichens are composed of intricately branched filaments that can hang from trees.
• Some horsehair lichens, such as Bryoria fremontii, have been referred to as "edible horsehair" and used as a traditional food, which could be of interest to pets.

Considerations for Children

• The filamentous structure of horsehair lichens may present a choking hazard for small children.

Taxonomy and Nomenclature

• Scientific Name: Primarily members of the genus Bryoria, formerly members of the genus Alectoria.
• Common Names: Horsehair lichen, tree hair lichen, black tree lichen, edible horsehair.
• Family: Parmeliaceae
• Kingdom: Fungi
• Taxonomic Rank: Genus
• Synonyms include horsetail lichen

Distribution and Habitat

• Widespread distribution, especially in boreal and cool temperate areas.
• Frequently found hanging from conifers, and less frequently hardwoods, in old-growth forest habitats.
• Observed in locations such as eastern Washington, Okanagan National Forest (Washington, USA), Glen Affric, and upstate Washington.

Morphological Characteristics

• Composed of intricately branched filaments resembling hair.
• Thallus color ranges from pale gray to dark smoky brown.
• Thallus hangs in clumps with slender strands containing long narrow slits on the surface.

Traditional Uses

• Some horsehair lichens (e.g., black horsehair lichen, green old man's beard lichen) have been used by indigenous groups like the Kootenais, Salish, and Blackfeet as a traditional food.

Interactions with Other Organisms

• May be found growing alongside other lichens, such as wolf lichen (Letharia vulpina) on trees like ponderosa pine.

Further Information

• Smithsonian Institution, National Museum of Natural History, Department of Botany has resources.