Sergey Yakovlevich Kondratyuk

Xanthomendoza is a genus of small, bright orange foliose lichens with lecanorine apothecia. It is in the family Teloschistaceae. Members of the genus are commonly called sunburst lichens or orange lichens because of their bright orange color. Members of Xanthomendoza were formerly classified in the genus Xanthoria, but Xanthomendoza members have rhizenes or scattered holdfasts, while Xanthoria do not, and they have different conidia. Lichen spot tests on the upper cortex are K+ purple, KC−, C−, and P−.

Xanthomendoza oregana is a species of corticolous (bark-dwelling), foliose lichen in the family Teloschistaceae. It forms an orange to bright-yellow thallus with ascending lobes that gives it the overall appearance of a tuft. The lichen occurs in western and northern Europe and western North America.

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Rusavskia elegans (formerly Xanthoria elegans), commonly known as the elegant sunburst lichen, is a lichenized species of fungus in the genus Rusavskia, family Teloschistaceae. Recognized by its bright orange or red pigmentation, this species grows on rocks, often near bird or rodent perches. It has a circumpolar and alpine distribution. It was one of the first lichens to be used for the rock-face dating method known as lichenometry.

Candelariella boikoi is a species of corticolous (bark-dwelling) crustose lichen in the family Candelariaceae. The lichen forms irregular, pale grey to grey-green patches on woody substrates, primarily colonizing the thickened twigs and branch bases of Halocnemum strobilaceum in arid, saline Eurasian semi-desert steppes. Unlike the common egg-yolk lichen Candelariella aurella, C. boikoi lacks a proper cortical skin and instead features a mosaic of algal cells embedded in fungal tissue, with abundant yellow-disced fruiting bodies rimmed by a distinctive golden-yellow margin.

Caloplaca wallabyensis is a species of crustose lichen in the family Teloschistaceae. Found in Australia, it was formally described as a new species in 2010 by lichenologists John Alan Elix, Sergey Kondratyuk, and Ingvar Kärnefelt. The type specimen was collected by Elix in Western Australia's Wallaby Hills Nature Reserve, for which the species is named. Here it was found growing on an old termite mound in Eucalyptus salmonophloia woodland with Xanthorrhoea shrubs and laterite rocks. It is known only from the type locality, where it is common. The lichen has a thallus that is 1–2 cm (0.4–0.8

Zeroviella is a genus of lichen-forming fungi in the subfamily Xanthorioideae of the family Teloschistaceae. It has eight saxicolous (rock-dwelling) species. Zeroviella was segregated from Rusavskia, a closely related genus, in 2015.

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Oxneria fallax, also known as the hooded sunburst lichen, is a small yellow-orange to red-orange foliose lichen that grows on bark or rarely on rock or bone. It is found all over the world except very dry areas. In Nepal, O. fallax has been reported from 3,200 to 3,400 m elevation in a compilation of published records. The non-fruiting body (thallus) grows in rosettes to 3 cm in diameter. The rosettes sometimes coalesce with each other. The lobes may appear divided at the tips. It is sometimes tightly appressed to the substrate (adnate), and sometimes not. The fruiting bodies (apothecia) are

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Rusavskia is a genus of lichen-forming fungi in the family Teloschistaceae. It has 12 species. It is a member of the subfamily Xanthorioideae. The thallus of Rusavskia is characterised by its foliose (leaf-like) structure with distinct and typically narrow lobes that curve outwards.

Marchantiana is a genus of lichen-forming fungi in the family Teloschistaceae. It contains seven species of corticolous (bark-dwelling), crustose lichens, recorded mainly from Australia. Originally proposed in 2014, the genus underwent significant revision in 2024 when molecular studies showed it comprised two distinct evolutionary lineages. This led to the creation of the new genus Taedigera to accommodate the cool-temperate species from New Zealand and Patagonia, while Marchantiana was retained for the warmer-climate Australian species. Later DNA-based work has treated Streimanniella as a

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Gallowayella is a genus of lichen-forming fungi in the family Teloschistaceae. It has 15 species. The genus was circumscribed in 2012 by Sergey Kondratyuk, Natalya Fedorenko, Soili Stenroos, Ingvar Kärnefelt, Jack Elix, and Arne Thell, with Gallowayella coppinsii assigned as the type species. The generic name honours New Zealand lichenologist David John Galloway (1942–2014).

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Caloplaca magnussoniana is a species of crustose lichen in the family Teloschistaceae. This small orange-brown lichen forms crusty patches on both volcanic rocks like dolerite and basalt, as well as limestone surfaces in sheltered but well-lit locations. It is found in temperate southeastern Australia, particularly in Victoria and Tasmania, from sea level up to about 600 metres elevation. The species is named after the Swedish lichenologist Adolf Hugo Magnusson and can be distinguished from similar species by its tightly clustered fruiting bodies and unique microscopic features including

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Honeggeria is a single-species fungal genus in the family Teloschistaceae. It contains the species Honeggeria rosmarieae, a corticolous (bark-dwelling), foliose lichen found in the United States. Characteristic features of the lichen include its isidia-like soredia, rhizines that are relatively broad and short, slender ascospores, and a rudimentary true exciple with a textura intricata tissue structure.

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Wolseleyidea is a genus of lichen-forming fungi in the family Ramalinaceae. It consists of six species. The genus was established in 2019 based on DNA analysis that showed these species form a distinct evolutionary lineage separate from the related genus Phyllopsora. Species are characterised by thin, granular thalli with a distinctive reddish-brown prothallus border, small brown disc-shaped fruiting bodies, and a chemical profile that includes methyl 2,7-dichloropsoromate and related compounds. The genus is named in honour of the British lichenologist Pat Wolseley for her contributions to

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Tomnashia is a genus of lichen-forming fungi in the family Teloschistaceae. It has four species of saxicolous (rock-dwelling), crustose lichens that occur in southwestern North America.

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Sedelnikovaea is a genus of placodioid lichens in the family Lecanoraceae. The genus was circumscribed in 2015 by Sergey Kondratyuk, Min-Hye Jeong, and Jae-Seoun Hur to contain Sedelnikovaea baicalensis, the type species. Three additional species were transferred into the genus in 2019. Sedelnikovaea resembles Protoparmeliopsis, and has a thallus that is placodioid (crustose at the centre and lobed at the periphery), and rosette-like. It has, however, a unique different ascus structure, and it is genetically distinct from Protoparmeliopsis. The genus name honours Russian lichenologist Nellia