Chrysothrix

Chrysothrix is a genus of lichen-forming fungi in the family Chrysotrichaceae. They are commonly called gold dust lichens or sulfur dust lichens, because they are bright yellow to greenish-yellow, sometimes flecked with orange, and composed entirely of powdery soredia. Apothecia are never present in North American specimens.

They grow on bark or rocks, generally in shaded habitats. They can sometimes be mistaken for sterile specimens of Chaenotheca, which usually has pinhead apothecia on tiny stalks, or Psilolechia, which usually has small, bright yellow apothecia. Chrysothrix chlorina was traditionally used as a brown dye for wool in Scandinavia.

Taxonomy
The genus was circumscribed by French botanist Camille Montagne in 1852, with Chrysothrix noli-tangere assigned as the type species.

In 2012, Jack Laundon submitted a formal proposal to conserve the name Chrysothrix against Alysphaeria, published 25 years earlier than Chrysothrix, citing the need for "nomenclatural stability". The proposal was accepted by the Nomenclature Committee for Fungi in 2017, who noted that Chrysothrix was already conserved against Pulveraria.

Species

 * Chrysothrix bergeri LaGreca (2020) – southeastern United States; the Caribbean; Bermuda
 * Chrysothrix caesia (Flot.) Ertz & Tehler (2011)
 * Chrysothrix candelaris (L.) J.R.Laundon (1981)
 * Chrysothrix chamaecyparicola Lendemer (2010) – eastern North America
 * Chrysothrix chilensis D.Liu & J.-S Hur (2018) – Chile
 * Chrysothrix chlorina (Ach.) J.R.Laundon (1981)
 * Chrysothrix chrysophthalma (P.James) P.James & J.R.Laundon (1981)
 * Chrysothrix citrinella Aptroot & M.Cáceres (2017)
 * Chrysothrix flavovirens Tønsberg (1994)
 * Chrysothrix frischii Kalb (2001)
 * Chrysothrix galapagoana K.Knudsen & Bungartz (2013)
 * Chrysothrix granulosa G.Thor (1988) – South America
 * Chrysothrix insulizans R.C.Harris & Ladd (2008)
 * Chrysothrix noli-tangere (Mont.) Mont. (1852)
 * Chrysothrix occidentalis Elix & Kantvilas (2007) – Australia
 * Chrysothrix oceanica Räsänen (1944)
 * Chrysothrix onokoensis (Wolle) R.C.Harris & Ladd (2008)
 * Chrysothrix palaeophila Kantvilas & Elix (2007) – Australia
 * Chrysothrix pavonii (Fr.) J.R.Laundon (1981)
 * Chrysothrix placodioides G.Thor (1988) – South America
 * Chrysothrix septemseptata Jagad.Ram, Lumbsch, Lücking & G.P.Sinha (2006) – India
 * Chrysothrix susquehannensis Lendemer & Elix (2010) – eastern North America
 * Chrysothrix tchupalensis Elix & Kantvilas (2007) – Australia
 * Chrysothrix xanthina (Vain.) Kalb (2001)