''Inonotus andersonii'', also known as oak canker-rot and heart rot, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of resupinate polypore fungus that forms fruiting bodies underneath tree bark. ''I. andersonii'' induces canker rot in

oak An oak is a hardwood tree or shrub in the genus ''Quercus'' of the beech family. They have spirally arranged leaves, often with lobed edges, and a nut called an acorn, borne within a cup. The genus is widely distributed in the Northern Hemisp ...

hickory Hickory is a common name for trees composing the genus ''Carya'', which includes 19 species accepted by ''Plants of the World Online''. Seven species are native to southeast Asia in China, Indochina, and northeastern India (Assam), and twelve ...

, cottonwood, and

willow Willows, also called sallows and osiers, of the genus ''Salix'', comprise around 350 species (plus numerous hybrids) of typically deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions. Most species are known ...

trees. Wood that has been infected by this species appears bleached of color and crumbles easily. Where sapwood decay reaches the cambium, the cambium may be killed, giving rise to an externally visible canker. The cankers caused by ''I. andersonii'' are commonly elongate and may become callused at the edges. The bark near expanding or developing cankers may also ooze varying amounts of dark sap. Affected branches or trees may show general symptoms of decline including poor growth, thinning, dieback, epicormic shoots (short twiggy branches arising from dormant buds on large-diameter stems) and branch or trunk failures. Generally, trees with canker rots decline slowly, often appearing to die from the top down as they slowly fall apart over a period of many years. The fruiting bodies (

basidiocarps In fungi, a basidiocarp, basidiome, or basidioma () is the sporocarp of a basidiomycete, the multicellular structure on which the spore-producing hymenium is borne. Basidiocarps are characteristic of the hymenomycetes; rusts and smuts do no ...

) of this fungus may appear on living trees or on recently failed stems. ''I. andersonii'' is "a true pathogen of living trees with a pronounced specificity for oak,

hat A hat is a Headgear, head covering which is worn for various reasons, including protection against weather conditions, ceremonial reasons such as university graduation, religious reasons, safety, or as a fashion accessory. Hats which incorpor ...

exhibits annual, widely effused fruitbodies, monomitic hyphal system, and broadly ellipsoid, yellowish, thick-walled basidiospores." ''Inonotus andersonii'' and similar canker rots are serious pathogens of California oaks and are associated with oak decline, failure, and mortality in many

California oak woodland California oak woodland is a plant community found throughout the California chaparral and woodlands ecoregion of California in the United States and northwestern Baja California in Mexico. Oak woodland is widespread at lower elevations in coast ...

Inonotus andersonii imported from iNaturalist photo 9132830 on 15 March 2024

References

{{taxonbar, from=Q10535883 andersonii Natural history of the California chaparral and woodlands Plant pathogens and diseases Fungus species

See also

References