''Nephroma'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of medium to large foliose lichens. The genus has a widespread distribution. They are sometimes called kidney lichens, named after the characteristic kidney-shaped

apothecia An ascocarp, or ascoma (), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. Ascocarps are mos ...

that they produce on the lower surface of their lobe tips, which often curl upwards and thus are visible from above. Sterile specimens that do not have apothecia can look somewhat like '' Melanelia'', ''

Peltigera ''Peltigera'' is a genus of approximately 100 species of foliose lichens in the family Peltigeraceae. Commonly known as the dog or pelt lichens, species of ''Peltigera'' are often terricolous (growing on soil), but can also occur on moss, trees, ...

'', '' Platismatia'', or '' Asahinea''. Most species grow either on mossy ground or rocks, or on trees. All species of ''Nephroma'' contain cyanobacteria (in the genus ''

Nostoc ''Nostoc'', also known as star jelly, troll’s butter, spit of moon, fallen star, witch's butter (not to be confused with the fungi commonly known as witches' butter), and witch’s jelly, is the most common genus of cyanobacteria found in var ...

'') as a

photobiont A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.fix nitrogen. In some species the cyanobacteria is the sole photobiont, while other species also contain a

green alga The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as ...

photobiont ('' Coccomyxa'') and the cyanobacteria is restricted to warty cephalodia on the upper or lower surface of the lichen.

Description

Species of ''Nephroma'' have a stratified foliose

thallus Thallus (plural: thalli), from Latinized Greek (), meaning "a green shoot" or "twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. Many of these organisms ...

with a cortex that is well-developed on both the upper and lower surfaces. The fruit bodies (

) 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 Peltigerales is an order of lichen-forming fungi belonging to the class Lecanoromycetes in the division Ascomycota. The taxonomy of the group has seen numerous changes; it was formerly often treated as a suborder of the order Lecanorales. It co ...

, the asci of ''Nephroma'' have neither a gelatinous coat nor an iodine-positive apical ring. The brown

ascospore An ascus (; ) is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores (or octad), produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some genera or ...

s are elongated, and have a crosswise partition (septa). Reproductive structures called

soredia Soredia are common reproductive structures of lichens. Lichens reproduce asexually by employing simple fragmentation and production of soredia and isidia. Soredia are powdery propagules composed of fungal hyphae wrapped around cyanobacteria or ...

isidia An isidium is a vegetative reproductive structure present in some lichens. Isidia are outgrowths of the thallus surface, and are corticated (i.e., containing the outermost layer of the thallus), usually with a columnar structure, and consisting ...

, or lobules are present in most species.

Species

*'' Nephroma arcticum'' *'' Nephroma australe'' *'' Nephroma bellum'' *'' Nephroma cellulosum'' *'' Nephroma expallidum'' *'' Nephroma flavorhizinatum'' *'' Nephroma helveticum'' *'' Nephroma laevigatum'' *'' Nephroma parile'' *'' Nephroma resupinatum'' *'' Nephroma rufum'' *'' Nephroma subhelveticum'' *'' Nephroma tangeriense''

Uses

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. ''Nephroma occultum'' is listed as vulnerable in Canada by COSEWIC. One species of ''Nephroma'' has been found to produce a brown dye, while another is recorded as being used in Scotland to produce a blue dye for wool. ''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. ''N. arcticum'' contains several

antifreeze protein Antifreeze proteins (AFPs) or ice structuring proteins refer to a class of polypeptides produced by certain animals, plants, fungi and bacteria that permit their survival in temperatures below the freezing point of water. AFPs bind to small ...

s that have been

patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A ...

ed by the Dutch

multinational corporation A multinational company (MNC), also referred to as a multinational enterprise (MNE), a transnational enterprise (TNE), a transnational corporation (TNC), an international corporation or a stateless corporation with subtle but contrasting senses, i ...

Unilever Unilever plc is a British multinational consumer goods company with headquarters in London, England. Unilever products include food, condiments, bottled water, baby food, soft drink, ice cream, instant coffee, cleaning agents, energy dri ...

for their ability to modify the growth of

ice crystals Ice crystals are solid ice exhibiting atomic ordering on various length scales and include hexagonal columns, hexagonal plates, dendritic crystals, and diamond dust. Formation The hugely symmetric shapes are due to depositional growth, n ...

; these proteins have been used to improve the texture of low-fat ice cream.

References

{{Authority control Lichen genera Peltigerales Taxa named by Erik Acharius Peltigerales genera Taxa described in 1810