''Candelariella clarkiae'' is a rare species of crustose lichen in the family

Candelariaceae ''Candelariaceae'' is a family of lichen-forming fungi in the order Candelariales. It contains seven genera and about 73 species. The family was circumscribed by Finnish lichenologist Rainar Hakulinen in 1954 to contain the type genus In biolo ...

. It was discovered in Colorado, USA, and formally described as a new species in 2015 by lichenologists Erin Tripp and James Lendemer. It was originally published with the species epithet ''clarki'', but this was subsequently corrected to ''clarkiae''. The name honors Dina Clark, Collections Manager at the University of Colorado

herbarium A herbarium (plural: herbaria) is a collection of preserved plant specimens and associated data used for scientific study. The specimens may be whole plants or plant parts; these will usually be in dried form mounted on a sheet of paper (called ...

, for her significant contributions to the knowledge of the Colorado flora, particularly the

high plains High Plains refers to one of two distinct land regions: * High Plains (United States), land region of the western Great Plains *High Plains (Australia) The High Plains of south-eastern Australia are a sub-region, or more strictly a string of adja ...

ecosystems flanking the Southern Rocky Mountains. The authors note of the lichen that "it is bright and sunny, just like Dina’s disposition". It is a crustose, saxicolous (rock-dwelling) lichen, composed of irregularly shaped with a

chartreuse Chartreuse () may refer to: Food and drink * Chartreuse (liqueur), a French liqueur * Chartreuse (dish), a French dish of vegetables or meat tightly wrapped in vegetable leaves and cooked in a mould Religion * Carthusians, a Catholic religi ...

thallus color. It lacks soredia, isidia, or other lichenized

diaspore Diaspore , also known as diasporite, empholite, kayserite, or tanatarite, is an aluminium oxide hydroxide mineral, α-AlO(OH), crystallizing in the orthorhombic system and isomorphous with goethite. It occurs sometimes as flattened crystals, bu ...

s. The apothecia are frequent but often lack mature

asci ASCI or Asci may refer to: * Advertising Standards Council of India * Asci, the plural of ascus, in fungal anatomy * Accelerated Strategic Computing Initiative * American Society for Clinical Investigation * Argus Sour Crude Index * Association of ...

and . This lichen differs from its closest relative, ''

Candelariella rosulans ''Candelariella'' is a genus of bright yellow, ocher, or greenish yellow crustose or squamulose lichens in the family Candelariaceae. Members of the genus are commonly called eggyolk lichens, goldspeck lichens, or yolk lichens. The genus was cir ...

'', in several ways, including its thallus color, apothecia shape, and chemical composition. ''Candelariella clarkii'' is known only from the type locality, where it was found occupying sunbaked, horizontal surfaces of very loose, fragile sandstones of the Fox Hills Formation. According to the authors, ''Candelariella clarkii'' merits ranking under the IUCN Red List as Critically Endangered due to its limited geographical range, small number of known extant populations, and the small number of individuals known.

References

{{Taxonbar, from=Q21259826 clarkiae Lichen species Lichens described in 2015 Lichens of the Northwestern United States Taxa named by James Lendemer