[3] Originally described scientifically by the Swedish lichenologist Erik Acharius over 200 years ago, it has been shuffled to many different genera in its taxonomic history before finally being transferred to Chrysothrix in 1981.

The lichen thallus is a yellow to yellow-green layer of fungi and green algae that are bundled together in powdery clumps called soredia.

Acharius's Latin diagnosis (crustaceus pulverulentus sublanuginosus pulvinato conglomeratus mollis flavissimus) characterized the lichen as crusty, powdery, slightly woolly, cushioned, clustered, soft, and very yellow.

They noted that when scraped from rocks, the yellow propagules remained stuck together in cushion-like masses, which floated on water and resisted submersion.

This absence of sexual features poses challenges in its classification, as these structures often provide critical characters used to distinguish between closely related lichen species.

This yellow fungus, found growing on the underside of the Lanyon Quoit, a dolmen in Cornwall, England, was illustrated in his work Coloured Figures of English Fungi or Mushrooms.

[8] In 2013, the lichenologists Kerry Knudsen and Frank Bungartz expressed concerns regarding the consistent classification of C. candelaris, suggesting it remains a heterogenous species and is often misidentified, particularly in Europe and North America.

Historically, Laundon identified these pigments using microcrystal tests,[5] but contemporary analyses prefer more sensitive methods like thin-layer chromatography.

[17] While Laundon's 1981 study suggested the lichen possessed a single chemotype containing calycin and vulpinic acid,[5] subsequent research indicates greater chemical variability.

Moreover, lichen samples from Antarctica presented a unique chemotype, consisting solely of vulpinic acid—a composition not reported in other regions.

Meanwhile, Psilolechia lucida features a yellowish-green, powdery thallus that appears less vibrant than that of C. chlorina, attributed to the presence of rhizocarpic acid.

Morphologically, it has a thinner crust, grows on different substrates, such as moss cushions and pockets of soil or organic matter on shaded vertical rock outcrops, and is only known to occur in Pennsylvania, USA.

[22] A study in the Suruli watershed of the Southern Western Ghats documented Chrysothrix chlorina on various substrates: bark, rock, wood, leaves, moss, and ground.

[26] Evidence suggests that pulvinic acid derivatives serve a protective role for the lichen, deterring specific herbivores and exhibiting antibacterial activity against gram-positive bacteria.

[28] In the early 19th century, the Swedish physician and naturalist Johan Peter Westring (1753–1833) conducted research on the dyeing potential of various lichens, documenting his findings in 1805.

[30] Westring's experiments with this lichen yielded a spectrum of 14 distinct colours, ranging from pale yellow and spanning green, blue, red, brown, culminating in an almost black hue.