''Candelaria pacifica'' is a widely distributed

corticolous This glossary of mycology is a list of definitions of terms and concepts relevant to mycology, the study of fungi. Terms in common with other fields, if repeated here, generally focus on their mycology-specific meaning. Related terms can be found ...

(bark-dwelling), leprose lichen. It was

formally described A species description is a formal scientific description of a newly encountered species, typically articulated through a scientific publication. Its purpose is to provide a clear description of a new species of organism and explain how it differ ...

as a species in 2011.

Taxonomy

''Candelaria pacifica'' was formally described as a species in 2011 by Martin Westberg and Ulf Arup. Before that, it was often mistaken for other species in the '' Candelaria'' genus. Since its discovery, many older records have been reviewed and many

herbarium A herbarium (plural: herbaria) is a collection of preserved plant biological specimen, 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 sh ...

specimens that were previously mislabeled have been reassessed as ''Candelaria pacifica''.

Description

Small, lobate

thallus Thallus (: thalli), from Latinized Greek (), meaning "a green shoot" or "twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. A thallus usually names the entir ...

up to 1 cm wide, shrubby appearance. Lobes are 0.1–0.6 mm wide.

Soredia Soredia are common reproduction, reproductive structures of lichens. Lichens asexual reproduction, reproduce asexually by employing simple fragmentation and production of soredia and isidia. Soredia are powdery propagules composed of fungus, fung ...

formed on lobe tips and in margins, present on the lower side. Upper cortex is yellow, with shades of lemon, orange, or green present, smooth, up to 45 μm thick. Medulla is white and thin, and lower cortex is lacking.

Rhizines In lichens, rhizines are multicellular root-like structures arising mainly from the lower surface. A lichen with rhizines is termed rhizinate, while a lichen lacking rhizines is termed erhizinate. Rhizines serve only to anchor the lichen to their s ...

are lacking.

Apothecia An ascocarp, or ascoma (: ascomata), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. As ...

are common, up to 1mm in diameter. Asci are clavate, containing 8 spores.

Ascospores In fungi, an ascospore is the sexual spore formed inside an ascus—the sac-like cell that defines the division Ascomycota, the largest and most diverse division of fungi. After two parental nuclei fuse, the ascus undergoes meiosis (halving of ...

are colorless, contain lipid droplets, ellipsoid.

Pycnidia A pycnidium (plural pycnidia) is an asexual fruiting body produced by mitosporic fungi, for instance in the order Sphaeropsidales ( Deuteromycota, Coelomycetes) or order Pleosporales (Ascomycota, Dothideomycetes). It is often spherical or inve ...

appear on surface as orange warts,

conidia A conidium ( ; : conidia), sometimes termed an asexual chlamydospore or chlamydoconidium (: chlamydoconidia), is an asexual, non- motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also ...

are ellipsoid. K, C, KC, P tests all negative on surface and medulla.

Similar species

Often mistaken for '' Candelaria concolor'', a differentiating aspect of ''C. pacifica'' is a lack or rare presence of rhizines. An 8 spored ascus is also present, compared to ''C. concolor'' which is polysporus. ''Candelaria pacifica'' also lacks a lower cortex and has soredia forming on the underside. Otherwise, both species are morphologically very similar. The formal declaration of ''C. pacifica'' as a species led to a review of herbarium specimens in many countries in Europe, in which it was found that many samples previously thought to be ''C. concolor'' were instead ''C. pacifica''. It even led to ''C. concolor'' being considered a common species in many counties to being considered rare.

Habitat and distribution

As a lichen, ''C. pacifica'' grows attached to a substrate while supporting a population of green algae in a symbiotic relationship within its thallus. It mainly inhabits the nutrient rich bark of deciduous trees. Occasionally present on coniferous trees. Often on free standing trees or at forest edges. Can also grow on dead bark and wood not attached to currently living trees. This species was first identified on the western coast of North America, where its range extends from the Sonoran Desert in the United States all the way up to the states of Washington and Idaho, stretching into Canada and South America. Its European distribution includes France, Belgium, Luxembourg, Poland, Estonia, Switzerland, Russia, Germany, the Netherlands, and Scandinavian counties. It has also been found in Iran.

References

{{Taxonbar, from=Q10453533 Candelariales Lichen species Lichens of Europe Lichens of North America Lichens of South America Lichens described in 2011 Lichens of Western Asia Taxa named by Ulf Arup