Karl Wilhelm Gottlieb Leopold Fuckel first described the species in 1861 under the basionym Fusidium vaccinii,[2] but in 1867 Mikhail Stepanovich Voronin (often cited as “Woronin”) later placed it in the genus Exobasidium.

[4] Exobasidium vaccinii, in current definition from John Axel Nannfeldt in 1981, is limited on the host Vaccinium vitis-idaea.

In its pathogenic state, E. vaccinii causes discoloration and, depending on the host, may cause hypertrophy and hyperplasia on the leaves and meristem, often forming flower-like structures (i.e. “pseudoflowers”).

Hyphae and haustoria contacting host cells cause significant amounts of pressure and subsequent distortion in the surrounding tissues.

[11] E. vaccinii is dimorphic and can be grown in culture; in its non-pathogenic state in nature, it likely lives in a yeast-like form in the soil or on the plant similar to many of its smut relatives.

Most species of native and cultivated rhododendron and azalea are considered susceptible, in addition to high and lowbush blueberry cultivars.

[5][7][12] E. vaccinii is distributed across the Northern Hemisphere, including most of eastern North America and western Europe, according to known studies.

[5] Additionally, lower fruit yields in systemically infected plants pose a great risk to commercial growers.

Originally E. vaccinii was a broad spectrum group but later studies showed it was a complex made of different species with narrow host ranges.