Candelaria fibrosa
{{Short description|Species of fungi}}
{{Speciesbox
| image = Candelaria fibrosa.jpg
| genus = Candelaria
| species = fibrosa
| authority = Müll.Arg.{{cite web |title=Candelaria fibrosa (Fr.) Müll.Arg. |url=https://www.gbif.org/species/5260444 |website=Gbif.org |access-date=30 December 2021 |language=en}}
}}
Candelaria fibrosa is a species of lichen-forming fungus. In English, it goes by the common name lemon lichen.{{Cite web|title=lemon lichen - Encyclopedia of Life|url=https://eol.org/pages/2859832|access-date=2021-11-18|website=Eol.org}} It also goes by the common name fringed candleflame lichen.{{cite web|url=http://minnesotaseasons.com/Destinations/LichenLists/Red_Rock_Prairie_Lichen_List_Bell.pdf|format=PDF|title=Red Rock Prairie : Lichen List|website=Minnesotaseasons.com|access-date=17 March 2022}} It occurs on the bark of wood, and it resembles Xanthoria hasseana.{{Cite book|last1=Brodo|first1=Irwin M.|url=https://books.google.com/books?id=YyS-hS15Ty4C&dq=Candelaria+fibrosa&pg=PA206|title=Lichens of North America|last2=Sharnoff|first2=Sylvia Duran|last3=Sharnoff|first3=Stephen|last4=Nature|first4=Canadian Museum of|date=2001-01-01|publisher=Yale University Press|isbn=978-0-300-08249-4|language=en}}{{Rp|page=206}}
Description
Candelaria fibrosa is a small foliose lichen with a thallus up to 4 cm wide. The lobes are dorsiventral, lobate, and imbricate, measuring approximately 0.5–2 mm wide and often bearing secondary lobes. The upper surface is lemon yellow to mustard yellow, smooth to somewhat wrinkled, and lacks both soredia and isidia. The upper cortex is about 5–20 µm thick, and the medulla is thin and white. The lower cortex measures approximately 10–35 µm thick and is white to pinkish in color. Rhizines are abundant and simple.Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1. | [https://lichenportal.org/portal/taxa/index.php?taxon=53262&clid=1074 Online excerpt]. Retrieved 17 June 2025.
Apothecia are common, laminal, and sessile, up to 2 mm in diameter, with a smooth margin that may have white or yellow cilia. The disc is darker yellow than the thallus. The epithecium is about 10 µm thick; the hymenium is 60–90 µm tall. Paraphyses are cylindrical to submoniliform, sometimes branched at the tips, with tip widths up to 5 µm. The hypothecium is 30–45 µm thick. Asci are clavate and contain more than 30 spores. Ascospores are uni- or biguttulate, colorless, and measure 7–11 × 4–6 µm. Pycnidia are common, immersed, and either concolorous with the upper surface or slightly darker. Conidia are ellipsoid to narrowly ellipsoid, measuring 2–3.5 × 1.5 µm.
Spot test results: upper surface K− (or K+ deeper yellow), C−, KC−, P−; medulla K−, C−, KC−, P−. Secondary metabolites include calycin (major) and pulvinic dilactone (minor).