genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of medium to large foliose
lichen
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.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 mo ...
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
''Melanelia'' is a genus of lichenized fungi in the family Parmeliaceae. The genus was circumscribed
In geometry, the circumscribed circle or circumcircle of a polygon is a circle that passes through all the vertices of the polygon. The cent ...
'', ''
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
Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blu ...
(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 vari ...
'') 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
''Coccomyxa'' is a genus of green algae
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) h ...
'') and the cyanobacteria is restricted to warty
cephalodia {{Short description, Morphological structure found in some lichens
Cephalodia (singular cephalodium) are small gall-like structures found in some species of lichens that contain cyanobacterial symbionts
Symbiosis (from Greek , , "living toget ...
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 wer ...
with a cortex that is well-developed on both the upper and lower surfaces. The fruit bodies (
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 mo ...
) are formed on the lower surface of the thallus, which is later curved backward to expose the
hymenium
The hymenium is the tissue layer on the hymenophore of a fungal fruiting body where the cells develop into basidia or asci, which produce spores. In some species all of the cells of the hymenium develop into basidia or asci, while in others some ...
(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 con ...
, the
asci ASCI or Asci may refer to:
* Advertising Standards Council of India
* Asci, the plural of ascus, in fungal anatomy
* Accelerated Strategic Computing Initiative
* American Society for Clinical Investigation
* Argus Sour Crude Index
* Association of ...
of ''Nephroma'' have neither a gelatinous coat nor an
iodine
Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at , and boils to a vi ...
-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 ...
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 gr ...
,
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 o ...
, or lobules are present in most species.
Species
*''
Nephroma arcticum
''Nephroma'' is a genus 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 that they produce on the lower surface of their ...
Nephroma expallidum
''Nephroma'' is a genus 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 that they produce on the lower surface of their ...
''
*''
Nephroma flavorhizinatum
''Nephroma'' is a genus 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 that they produce on the lower surface of their ...
Several species of ''Nephroma'' are restricted to pristine, old growth forests, and thus are important
indicator species
A bioindicator is any species (an indicator species) or group of species whose function, population, or status can reveal the qualitative status of the environment. The most common indicator species are animals. For example, copepods and other sma ...
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 i ...
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 p ...
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 drink, t ...
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, na ...
; these proteins have been used to improve the texture of low-fat ice cream.