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Candelariella athallina (Wedd.) Du Rietz
Family: Candelariaceae
Candelariella athallina image
Thompson, J., 1997. American Arctic Lichens: The Microlichens.
Thallus lacking or of minute dispersed granules, yolk-colored. Apothecia flat and considerably smaller than those of C. vitellina, to 0.7 mm broad; margin entire, rarely crenulate; hypothecium hyaline; epithecium rough, slightly shining when young, 6-18 μm thick, clear yellow, not much distinct from the margin; hymenium hyaline, 50-60 μm, 1+ blue; paraphyses slightly capitate, 2-2.5 μm, tips slightly thicker; asci broadly clavate; spores 32-36 per ascus, ellipsoid, often poorly formed, with one or sometimes both ends pointed, filled with oil drops which sometimes give the appearance of 2-celled spores, straight or slightly curved, 9-15 x 4-6 μm.

This species is found in fissures and holes in acidic rocks, particularly along seashores, and is suggested by Hakulinen (1954) to be even more strongly ammoniophilous than C. vitellina. Previously known from Scandinavia and France, it also occurs in North America, ranging from the Arctic to Colorado and Arizona.

This species has a close resemblance to C. aurella, which likewise may lack a thallus but has only 8 spores per ascus.