''Insolibasidium deformans'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

fungus 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 ...

belonging to the

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...

Platygloeales The Platygloeales are an order of rust fungi in the class Pucciniomycetes. It contains two families, the '' Eocronartiaceae'' and also the '' Platygloeaceae''. Order Platygloeales are monophyletic group (they have a common ancestor). The resul ...

. It is currently the only species in the

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

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 ...

''Insolibasidium''. The fungus parasitizes leaves of various ''

Lonicera Honeysuckles are arching shrubs or twining vines in the genus ''Lonicera'' () of the family Caprifoliaceae, native to northern latitudes in North America and Eurasia. Approximately 180 species of honeysuckle have been identified in both contin ...

'' species, causing honeysuckle leaf blight, a commercially significant disease in plant nurseries. The known hosts for ''Insolibasidium deformans'' include at least 18 species of ''Lonicera''. The fungus parasitizes host leaves, producing hyphae within the leaf tissues and

basidia A basidium () is a microscopic sporangium (a spore-producing structure) found on the hymenophore of fruiting bodies of basidiomycete fungi which are also called tertiary mycelium, developed from secondary mycelium. Tertiary mycelium is highly-c ...

that protrude through the

stomata In botany, a stoma (from Greek ''στόμα'', "mouth", plural "stomata"), also called a stomate (plural "stomates"), is a pore found in the epidermis of leaves, stems, and other organs, that controls the rate of gas exchange. The pore is bor ...

. Microscopically, the

are auricularioid (tubular with lateral septa). Infected leaves become yellow, then brown, and finally dead and dry with brown areas. Leaves often become rolled and twisted and drop prematurely. The species is native to North America and has been introduced into the UK where honeysuckle leaf blight was first observed in 2000 and into Australia, where the disease was first observed in 2003. It has also been recorded from Germany, Poland, and New Zealand.

References

{{Taxonbar, from1=Q10536045, from2=Q10536047 Pucciniomycotina Fungi of North America Fungal plant pathogens and diseases