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Ethnobotany - Lichens


Bryoria fremontii (Black tree lichen)
Letharia vulpina (Wolf lichen)
Usnea longissima (Methuselah's beard)

By Scott Clay-Poole, PhD

Bryoria fremontii - Black Tree-lichen, Black "Moss", Bear Hair

Bryoria fremontii 
Black Tree-Lichen, Black "Moss", Bear Hair

A dark-colored, filamentous lichen hanging from the branches of coniferous trees; 4-24" long. When dry, the thallus is stiff and wiry, when wet, it is soft and limp. The individual branches, or filaments are round to flattened, smooth, and much entangled. Bryoria fremontii differs from several closely related, inedible species with which it may grow by its characteristically twisted dark, reddish-brown to chocolate-brown main branches, often flattened or pitted here and there, with short, much more slender, perpendicular side branches. Spore-bearing structures are uncommon. The greenish-yellow pigment in this and related species is a bitter, potentially toxic pulvinic acid derivative unique to lichens called vulpinic acid.

Habitat: On branches of (usually) coniferous trees such as Douglas-fir, lodgepole pine, ponderosa pine, and western larch (shown above) in montane forests.

Use: This lichen is often referred to in ethnographic literature as Alectoria jubata. Most First Peoples call it "black moss". Populations of the lichen vary in taste. Some are bitter due to high concentrations of lichen acids. The taste is also affected by the type of tree the lichen is growing on. Some prefer the lichen from larch or Douglas-fir, though some prefer the lichen from the pines mentioned. The lichen could be gathered at any time of the year, but usually it was in late summer or early fall after the work with other foods was done.

Typically the lichen was harvested using any large pole, preferably with some kind of hook for grasping and twisting off.

Most First Peoples are said to boil the lichen and eat it with fish, grease, or berries. Many would taste test the lichen first to determine if it was too bitter. The harvested lichen was cleaned of debris, then soaked in running water and pounded in an attempt to remove the bitter, greenish vulpinic acid. It was then cooked in layers in underground steaming pits for as long as 24 hours. It could be eaten freshly cooked, or dried for winter use. Resembling gelatinous licorice in appearance after cooking, it is bland tasting. It was sometimes cooked with nodding onions (Allium cernuum) or other "root" foods to flavor it. Sometimes Saskatoon berry juice was added to it before drying. Because it could be gathered in relatively large quantities, and was available for harvesting year-round, it was an important emergency and famine food. At present this lichen is rarely used.

According to Okanogan-Colville (northeast Washington) mythology, black tree lichen is said to have originated from Coyote's hair. Coyote had attempted to capture some swans, but instead they flew into the air, taking him with them. The swans let go of Coyote when they were up high. He fell and became lodged in the branches of a tree. Finally he was able to free himself, leaving much of his hair entangled in the branches. Coyote then transformed this hair into black tree lichen, saying "You, my hair, will not be wasted. The coming people will gather you and make you into food." Thus he changed it to its present form and it has been used as food ever since (Turner et al., 1980).


Photo credit of lichen fromNorth American Lichen Project, Lichens of North America, Irwin M. Brodo, Sylvia Duran Sharnoff and Stephen Sharnoff, Yale University Press. 1998. 


Letharia vulpina - Wolf "Moss"

Letharia vulpina
Wolf "Moss"

There are two species of Letharia that are not easily distinguished; L. vulpina and L. columbiana. These two species are chemically very similar but different sexually. L. vulpina is usually not sexual and always has soredia (clonal symbiotic propagules, made of a weft of fungal hyphae surrounding a nest of algal cells), and L. columbiana is always sexual and does not have soredia. The size of L. vulpina can be as small as 1cm to as large as 12cm. L vulpina is heavily branched, L. columbiana less so. The branches are irregularly round and rather wrinkled, and quite so under very dry conditions. The thallus is more or less upright, standing out from the sides of tree trunks or branches. It often occurs in a thick, solid cover, particularly on dead trees and limbs. It is more abundant in edgier habitats where sunlight is more abundant. In Washington, it is often tangled with Bryoria.

The color ranges from a brilliant yellow green to a duller yellow ochre under drier conditions. It is the easiest lichen to spot, noticible even when driving at fast speed from the highway.

The apothecia (fruiting bodies, producing sexual spores) are light to dark brown, from 2 mm to 2 cm. The soredia are abundantly produced and rub off easily when examined.

Letharia vulpina is most commonly found in dry coniferous forests. The species also occurs in Europe southward to North Africa. The species is found on twigs and stumps of most conifers. In Washington, you won't find it in coastal Douglas-fir rain forests, but in drier inland Douglas-fir stands, where it can be very abundant. It seems to be adapted to summer dryness [in fact, the alga's photosynthetic maximum is 7oC, and doesn't drop much even to 0oC, (the freezing point)]. So it is active mostly during winter precipitation. There are, however, instances of the lichen found on bark of other trees, and human made substrates like houses and fence posts. It sometimes occurs on rocks.

Letharia vulpina seems to be restricted to localities with long ecological continuity, and often grows on old trees. While other lichens of old-growth forest seemingly prefer more or less productive forests where they get some kind of shade or shelter, though wolf moss thrives on wood even in sunny situations, also outside forests. The species is extremely photophilous, intolerant of canopy shade, and finds a niche in very open stands where waterlogged soils, nutrient-deficient soils and/or low temperatures limit growth and survival of trees.

Use: Used as a yellow dye. For this purpose it was boiled in water, alone or with Oregon grape bark. This dye was used mainly for basket materials and fibers. As a medicine, this lichen was boiled and taken in a weak solution for internal problems and, in stronger solution, was used to wash external sores and wounds.

This lichen is so poisonous that the Achomawi in Northern California used it to make poison arrowheads.

And how did the common name come about? It deals with the European usage, which (barbarians that they were) was destructive. It was mixed with ground glass and meat and used to kill wolves. The vulpinic acid is toxic, although it is not clear if the ground glass may have been enough to do the job. Perhaps it caused stomach perforations and allowed the vulpinic acid (note the name) to be readily absorbed. 

Photo credit of lichen from North American Lichen Project, Lichens of North America, Irwin M. Brodo, Sylvia Duran Sharnoff and Stephen Sharnoff, Yale University Press. 1998.

Plant and habitat description, as well as the source of the common name from Europe comes from Scott Kroken, a Ph.D. candidate at the University of California, Berkeley, who is currently working on his dissertation and Letharia.  


Usnea longissima - Methuselah's Beard
Enlarge photo

Usnea longissima
Methuselah's Beard

A large, hanging hair lichen, 15-35 cm or more long, pale yellowish-green, consisting of a single, unbranched (or sparsely branched) central strand and numerous short lateral branchlets; white central cord becoming in part exposed (decorticate); soredia absent; central cord white.

Habitat:  Over various trees and shrubs in open, well-ventilated forests; infrequent, but locally abundant. This species disperses mostly, if not entirely, from small pieces carried to new localities. It is best developed in old-growth forests and will probably not persist in short-rotation second-growth forests.

Use: Some First Peoples utilized the fibers of this plant to strain impurities from hot pitch before the pitch was used as medicine.

[Pojar & MacKinnon, 1994]
