|
|
Practical ecological knowledge for the temperate reader. |
| Local Genera | |
Genera Included; |
Genera Omitted; |
|
|
"The Lichen division is comprised of at least 8 orders, 45 families, and 6,000 species. Information on the edible and medicinal uses of lichens is scattered. Many lichens are known to have potent antibiotic properties, and many are edible. However, some lichens do contain toxic substances, so one should not graze randomly on them." [HPEP]
"Lichens are a unique complex of two types of plants, an alga and a fungus, growing together in a symbiotic relationship. Several types have been used as food in different parts of the world (Smith, 1921; Llano, 1944; Richardson, 1975) but most are difficult for humans to digest because of their complex polysaccharides. Additionally, many are bitter, irritating to the digestive tract, or even toxic, due to such lichen substances as vulpinic and usnic acids." [Turner&Kuhnlein]
"A lichen is a composite of a fungus and an alga. The alga combines carbon dioxide and oxygen with the sun''s energy into sugars that provide energy for the fungus. The fungus protects the alga within its tissues and provides a steadier supply of moisture. This association is so successful that there are about 500 species of macrolichens in the Pacific Northwest that can be identified with a guide such as "Macrolichens of the Pacific Northwest" by Bruce McCune and Linda Geiser. Even more are covered and illustrated in the superb volume "Lichens of North America" by Irwin M. Brodo, Sylvia Duran Sharnoff, and Stephen Sharnoff. "Mosses Lichens & Ferns of Northwest North America" by Vitt et al. and "The Lichens of British Columbia" by Goward et al. are also useful for lichens, the former for beginners, and the latter for definitive technical information. Worldwide, a fifth of known fungal species are said to be lichenized, according to McCune & Geiser. In most cases the fungi are ascomycetes but some, including the common gilled species Omphalina ericetorum and the club-shaped Multiclavula mucida are basidiomycetes. The algae are usually green algae, but about 15% of the lichens in the Pacific Northwest are associated with the blue-green algae Nostoc and Scytonema which can fix nitrogen from the air into forms usable by plants and animals. Some lichens are associated with both green and blue-green algae. (McCune & Geiser). The blue green algae are less closely related to the green algae than they are to the bacteria and are often called cyanobacteria. (Kendrick 1992)." [E-flora]
Hazards
Lichens, with two exceptions, are nonpoisonous, though some acid substances in others may be irritating when taken internally. The poisonous exceptions are Evernia vulpina and Cetraria pinastri, both a characteristic bright yellow. The former contains vulpinic acid in the cortical cells, the crystals of which are yellow in the mass. The latter species and Cetraria juniperina Ach. produce pinastrinic acid in the hyphae of the medulla, and the crystals are orange or golden-yellow. These lichens have been used in northern European countries to poison wolves by stuffing them and powdered glass into bait (18). Santesson isolated the crystalline acid and tested it on animals ; it produced respiratory difficulties, reducing the rate of breathing until death ensued.[EUL]
The distribution and shape of eczematous skin lesions suggests the possibility of allergic contact dermatitis. Plant sources of allergic contact dermatitis include ...liverwort (Frullania ) and lichens (Cladonia, Evernia, Parmelia, Usnea ).13,14 Occupational exposure to the latter two group produces a chronic, lichenified, dermatitis of the hands, forearms, face, and neck in forest workers and wood cutters (e.g., wood cutter ’ s dermatitis).15 These lesions often are photosensitive. [TNS]
Some lichens are quite toxic, due to the presence of usnic or vulpinic acid or other lichen substances. One example is wolflichen (Letharia vulpina and related spp.), a bright greenish yellow, finely branched fruticose type grow- ing on trunks and dead branches of coniferous trees in dry areas of north- western North America. In Scandinavia, wolf lichen was powdered, mixed with ground glass, and sprinkled on meat, as a wolf poison. Another notably poisonous species is ground lichen (Parmelia molliuscula) , a gray-green i rreg- ularly dissected, flattened type. It grows from Nebraska to North Dakota and west to the Rocky Mountains and has been responsible for range poisoning of sheep and cattle, sometimes causing severe paralysis and death. Poisoning usually occurs in winter when other forage is scarce. Some rel- atives of black tree hair lichen, including Bryoria tortuosa, contain much higher concentrations of poisonous vulpinic acid and are potentially toxic; usually, however, their bitter taste precludes people consuming them. [CPPlantMush]
Food Use
Several types have been used as food in different parts of the world but most are difficult for humans to digest because of their complex polysaccharides. Additionally, many are bitter, irritating to the digestive tract or even toxic, due to such lichen substances as vulpinic and usnic acids. Wolf lichen (Letharia vulpina), a bright yellow-green branching type growing on dry conifer wood and bark in western Canada, is an example. Its high vulpinic acid content makes in poisonous.[Turner&Kuhnlein]
"Lichen polysaccharides have been shown to be broken down into simple sugars in the digestive tracts of animals by the action of aerobic and anaerobic bacteria (Llano, 1944). Apparently, this is true in the human digestive tract as well, and, as with marine algae, if people eat lichens over a period of time,they are more easily handled by the body than if they are eaten on only one occasion. This is indicated by the following statement from Kari (1987): They...are stuck tight to the bark of the tree. ...The Lime Villagers [Tanaina of Alaska] say that some of these tree lichens taste sweet. They like to snack on them when they're out in the woods. They eat a little bit at a time. If you're not used to them, some of them might give you a stomach ache..." [Turner&Kuhnlein]
"Even lichens that were eaten were usually treated to remove some of the toxic components. Often, lichens were eaten only in times of scarcity. The Iroquois, for example, rarely ate lichens, but in emergencies, they scraped them from trees or rocks, washed them in ashes and water to remove the bitterness, then boiled them in grease before eating them (Parker, 1910; Arnason et al.,1981)." [Turner&Kuhnlein]
“Major species eaten traditionally include: black tree lichen (Bryoria fremontii); rock tripe (Actinogyra spp.,Umbilicaria spp.); and reindeer lichens (Cladina spp.), used fresh or collected partially digested from caribou rumens.” [Turner&Kuhnlein]
Pharmacology
"A novel species of Dictyonema was used by the Waorani as a hallucinogen." [HPEP]
Tree Lichen – Alectoria spp. & Usnea spp.; Boiled by the Lime Villiage Tanaina of Alaska and eaten with fish, grease, or berries.
"Bryoria were used by the Thompson and probably some other Interior Salish groups for making clothing. They were not considered a high quality material, however, and were usually used only by poorer people who could not obtain skins for clothing. Having a rather woolly texture, they provided good padding and insulation, but since they absorbed moisture quickly they were not very practical in wet weather. Little preparation was required in making lichen garments. Long strands of the lichen were cleaned and twisted together in loose coils about 1.5 cm (0.6 inches) thick. These were laid out side by side to form the shape of the garment--such as poncho or shoe to be made, then twined together at intervals with a fibrous material such as twisted Indian hemp (Apocynum cannabinum L.) or silverberry bark (Elaeagnus commutata Bernh.) (Turner, in press b) (see Fig. 4)." [Turner,1977]
Arctic kidney lichen – Nephroma arcticum - Boiled with crushed fish eggs, or cooked as strengthening food by Western Alaskan Eskimo.
Mentioned as a local species: Absent from .
Species Mentioned: Reindeer “moss” - Cladina rangiferina. Often reindeer lichen grows together with one or more related species in closely intermixed patches. Although distinguishable to the experienced eye, they are apparently all eaten by caribou and all would thus have been consumed by humans as well.”
Food use: Reindeer lichen and its relatives were apparently seldom used fresh by Indigenous Peoples except during times of emergency. The Inland Tanaina of Alaska boil it or soak it in hot water until it is soft, then eat it plain or mixed with berries, fish eggs or grease. They also cook it and feed it to their dogs.
The main food use of reindeer lichen as a major component of the partially digested stomach contents of caribou and other ungulates. Often mixed together with other lichens such as Cetraria, mushrooms, horsetails, sedges, grasses, willow, birch, and blueberry leaves and shoots, and other plant foods, it was considered a delicacy in this form. This food was used traditionally by most Inuit peoples (including Igloolik, Copper, Caribou, Netsilik, Baffin Island, Nuamiut, Labrador, and Polar), as well as by the Chipewyan and other northern Indian groups. Because the complex lichen polysaccharides and proteins were apparently partially broken down in the animal's rumen, this material was more easily digestible for humans.”
Porsild (1951) states that lichens were used as emergency food only by White travellers in the North, but not by Indigenous Peoples.
Consumed alone or as stomach contents of caribou.
Medicinal Use: It is sometimes boiled and eaten to stop diarrhea, but it is known to cause stomach trouble in some people if it is not cooked well.
References