''Cryphonectria'' is a

fungal A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from th ...

genus in the order

Diaporthales Diaporthales is an order of sac fungi. Wijayawardene et al. in 2020 added a number of name families to the order. Diaporthales includes a number of plant pathogenic fungi, the most notorious of which is '' Cryphonectria parasitica'' (Murrill) B ...

. The most well-known and well-studied species in the genus is ''

Cryphonectria parasitica The pathogenic fungus ''Cryphonectria parasitica'' (formerly ''Endothia parasitica'') is a member of the Ascomycota (sac fungi). This necrotrophic fungus is native to East Asia and South East Asia and was introduced into Europe and North America ...

'', the species which causes chestnut blight. The genus was, for a time, considered synonymous with '' Endothia'', but the two are now recognised as distinct. Taxonomic studies in 2006 limited the genus to four species, but a fifth, '' Cryphonectria naterciae'', was described in 2011 from Portugal.

Species

*'' Cryphonectria abscondita'' *'' Cryphonectria acaciarum'' *'' Cryphonectria cubensis'' *''

Cryphonectria decipiens ''Cryphonectria'' is a fungal genus in the order Diaporthales. The most well-known and well-studied species in the genus is ''Cryphonectria parasitica'', the species which causes chestnut blight. The genus was, for a time, considered synonymous ...

'' *'' Cryphonectria japonica'' *'' Cryphonectria macrospora'' *''

Cryphonectria moriformis ''Cryphonectria'' is a fungal genus in the order Diaporthales. The most well-known and well-studied species in the genus is ''Cryphonectria parasitica'', the species which causes chestnut blight. The genus was, for a time, considered synonymous ...

'' *'' Cryphonectria naterciae'' *''

Cryphonectria nitschkei ''Cryphonectria'' is a fungal genus in the order Diaporthales. The most well-known and well-studied species in the genus is ''Cryphonectria parasitica'', the species which causes chestnut blight. The genus was, for a time, considered synonymous ...

'' *''

Cryphonectria variicolor ''Cryphonectria'' is a fungal genus in the order Diaporthales. The most well-known and well-studied species in the genus is ''Cryphonectria parasitica'', the species which causes chestnut blight. The genus was, for a time, considered synonymous ...

'' According to Murr) (And.et And.)Chestnut blight was first discovered in North America in 1904 on '' Castanea dentata''. By the 1940s it had killed most wild American chestnut trees, which were formerly one of the most abundant species in the eastern U.S. The infection takes place through bark wounds. In the early stage, clear yellow-brown spots appear on the young twigs; the bark then splits open, sinks in and dies out. In the next stage the

cambium A cambium (plural cambia or cambiums), in plants, is a tissue layer that provides partially undifferentiated cells for plant growth. It is found in the area between xylem and phloem. A cambium can also be defined as a cellular plant tissue from w ...

layer is infected, the tree trunk becomes disformed, the split bark parts start to swell as parasitic fungus produces more peridermia and yellow colored

pycnidia A pycnidium (plural pycnidia) is an asexual fruiting body produced by mitosporic fungi, for instance in the order Sphaeropsidales ( Deuteromycota, Coelomycetes) or order Pleosporales (Ascomycota, Dothideomycetes). It is often spherical or inverse ...

start to appear on the bark. Then the tree's leaves wilt and branches start dying off. The release of fungal spores lasts through the whole vegetative season.

References

Diaporthales {{Sordariomycetes-stub