Nephroma | |
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Nephroma arcticum | |
Scientific classification
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Domain: | Eukaryota |
Kingdom: | Fungi |
Division: | Ascomycota |
Class: | Lecanoromycetes |
Order: | Peltigerales |
Family: | Peltigeraceae |
Genus: |
Nephroma Ach. (1809) |
Type species | |
Nephroma arcticum | |
Species | |
See text |
Nephroma is a genus of medium to large foliose lichens. The genus has a widespread distribution. [1] They are sometimes called kidney lichens, named after the characteristic kidney-shaped apothecia that they produce on the lower surface of their lobe tips, which often curl upwards and thus are visible from above. [2] Sterile specimens that do not have apothecia can look somewhat like Melanelia, Peltigera, Platismatia, or Asahinea. Most species grow either on mossy ground or rocks, or on trees. [2]
All species of Nephroma contain cyanobacteria (in the genus Nostoc) as a photobiont, which allows the organism to fix nitrogen. In some species the cyanobacteria is the sole photobiont, while other species also contain a green alga photobiont ( Coccomyxa) and the cyanobacteria is restricted to warty cephalodia on the upper or lower surface of the lichen. [2]
Species of Nephroma have a stratified foliose thallus with a cortex that is well-developed on both the upper and lower surfaces. The fruit bodies ( apothecia) are formed on the lower surface of the thallus, which is later curved backward to expose the hymenium (spore-bearing surface). Initially, the ascomata are immersed with a vegetative covering that splits open at later stages of development. In contrast to all other groups of Peltigerales, the asci of Nephroma have neither a gelatinous coat nor an iodine-positive apical ring. The brown ascospores are elongated, and have a crosswise partition (septa). Reproductive structures called soredia, isidia, or lobules are present in most species. [3]
Several species of Nephroma are restricted to pristine, old growth forests, and thus are important indicator species that have already influenced some forest management decisions. [2] Nephroma occultum is listed as vulnerable in Canada by COSEWIC.
One species of Nephroma has been found to produce a brown dye, [4] while another is recorded as being used in Scotland to produce a blue dye for wool. [5] Nephroma arcticum is called kusskoak by the Yup’ik of Alaska, and it is traditionally eaten after being boiled with crushed fish eggs. A medicinal tea is also made from the lichen, and is reputed to be a powerful medicine to return strength to a person who is in a weak condition. [6] N. arcticum contains several antifreeze proteins that have been patented by the Dutch multinational corporation Unilever for their ability to modify the growth of ice crystals; these proteins have been used to improve the texture of low-fat ice cream. [7]
Nephroma | |
---|---|
![]() | |
Nephroma arcticum | |
Scientific classification
![]() | |
Domain: | Eukaryota |
Kingdom: | Fungi |
Division: | Ascomycota |
Class: | Lecanoromycetes |
Order: | Peltigerales |
Family: | Peltigeraceae |
Genus: |
Nephroma Ach. (1809) |
Type species | |
Nephroma arcticum | |
Species | |
See text |
Nephroma is a genus of medium to large foliose lichens. The genus has a widespread distribution. [1] They are sometimes called kidney lichens, named after the characteristic kidney-shaped apothecia that they produce on the lower surface of their lobe tips, which often curl upwards and thus are visible from above. [2] Sterile specimens that do not have apothecia can look somewhat like Melanelia, Peltigera, Platismatia, or Asahinea. Most species grow either on mossy ground or rocks, or on trees. [2]
All species of Nephroma contain cyanobacteria (in the genus Nostoc) as a photobiont, which allows the organism to fix nitrogen. In some species the cyanobacteria is the sole photobiont, while other species also contain a green alga photobiont ( Coccomyxa) and the cyanobacteria is restricted to warty cephalodia on the upper or lower surface of the lichen. [2]
Species of Nephroma have a stratified foliose thallus with a cortex that is well-developed on both the upper and lower surfaces. The fruit bodies ( apothecia) are formed on the lower surface of the thallus, which is later curved backward to expose the hymenium (spore-bearing surface). Initially, the ascomata are immersed with a vegetative covering that splits open at later stages of development. In contrast to all other groups of Peltigerales, the asci of Nephroma have neither a gelatinous coat nor an iodine-positive apical ring. The brown ascospores are elongated, and have a crosswise partition (septa). Reproductive structures called soredia, isidia, or lobules are present in most species. [3]
Several species of Nephroma are restricted to pristine, old growth forests, and thus are important indicator species that have already influenced some forest management decisions. [2] Nephroma occultum is listed as vulnerable in Canada by COSEWIC.
One species of Nephroma has been found to produce a brown dye, [4] while another is recorded as being used in Scotland to produce a blue dye for wool. [5] Nephroma arcticum is called kusskoak by the Yup’ik of Alaska, and it is traditionally eaten after being boiled with crushed fish eggs. A medicinal tea is also made from the lichen, and is reputed to be a powerful medicine to return strength to a person who is in a weak condition. [6] N. arcticum contains several antifreeze proteins that have been patented by the Dutch multinational corporation Unilever for their ability to modify the growth of ice crystals; these proteins have been used to improve the texture of low-fat ice cream. [7]