''Teloschistes flavicans'', also known as the golden hair-lichen, is a

lichen A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...

ized species of

fungus A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

in the genus ''Teloschistes'' (meaning "split-ends"; a reference to the plant's finely divided

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 ...

and dense coils which appear almost like brillopads), family

Teloschistaceae The Teloschistaceae are a large family (biology), family of mostly lichen-forming fungi belonging to the class (taxonomy), class Lecanoromycetes in the division (botany), division Ascomycota. The family has a cosmopolitan distribution, althoug ...

. Recognized by its

saffron Saffron () is a spice derived from the flower of '' Crocus sativus'', commonly known as the "saffron crocus". The vivid crimson stigma and styles, called threads, are collected and dried for use mainly as a seasoning and colouring agent ...

-coloured pigmentation, this widespread

fruticose lichen A fruticose lichen is a form of lichen fungi that is characterized by a coral-like shrubby or bushy growth structure. It is formed from a symbiotic relationship of a photobiont such as green algae or less commonly cyanobacteria and one, two or m ...

grows on rocks and branches of trees.

Taxonomy

It was first named and

scientifically 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 diffe ...

in 1788 by the Swedish

botanist Botany, also called plant science, is the branch of natural science and biology studying plants, especially Plant anatomy, their anatomy, Plant taxonomy, taxonomy, and Plant ecology, ecology. A botanist or plant scientist is a scientist who s ...

Olof Swartz Olof Peter Swartz (21 September 1760 – 19 September 1818) was a Swedish botanist and taxonomist. He is best known for his taxonomic work and studies into pteridophytes, but also studied orchids, mosses and lichens. Biography Olof Swartz a ...

, who called it ''Lichen flavicans''. Johannes Norman transferred it to the genus '' Teloschistes'' in 1852.

Development

''Teloschistes flavicans'' has a distinctive growth pattern characterized by the formation of (specialized fungal outgrowths) at its branch tips. The

(body) of the lichen grows from (curved inward) apices that contain both fungal cells and photobiont (algal) cells in an unstratified arrangement. These growing points give rise to both the main branches and the characteristic cilia. The development of cilia begins with the appearance of a small, deeply orange-colored spot on the recurved surface of a branch tip. This develops into a primordium (early developmental structure) composed of elongated fungal

hypha A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one o ...

e that converge at the tip. Unlike the main branches, cilia contain no cells. Each cilium reaches a final length of 0.3–1 mm. While cilia can sometimes function as attachment structures by forming connections to like

bryophyte Bryophytes () are a group of embryophyte, land plants (embryophytes), sometimes treated as a taxonomic Division (taxonomy), division referred to as Bryophyta ''Sensu#Common qualifiers, sensu lato'', that contains three groups of non-vascular pla ...

leaves or other lichens, this appears to occur in only a small proportion of cases. The formation of a cilium typically coincides with the bifurcation (splitting) of the growing point into two new branches. When a cilium develops, the photobiont cells and associated fungal tissue are displaced to either side of its base, creating two new growing points. These initially face in opposite directions, creating a characteristic

fleur-de-lis The ''fleur-de-lis'', also spelled ''fleur-de-lys'' (plural ''fleurs-de-lis'' or ''fleurs-de-lys''), is a common heraldic charge in the (stylized) shape of a lily (in French, and mean and respectively). Most notably, the ''fleur-de-lis'' ...

pattern. New cilia often form at the tips of these branches before they elongate significantly, leading to further bifurcation. The branching pattern of ''T. flavicans'' often shows a regular arrangement, with successive branches forming at right angles to each other, creating a roughly cruciate (cross-shaped) pattern. This organized growth pattern is most evident in the younger, terminal portions of the thallus. In older parts, secondary branches arising from damaged areas or specialized reproductive structures (

soralia Soredia are common reproductive structures of lichens. Lichens reproduce asexually by employing simple fragmentation and production of soredia and isidia. Soredia are powdery propagules composed of fungal hyphae wrapped around cyanobacteria or g ...

) can obscure this regular pattern. While cilia typically form centrally between branch points, they can occasionally develop asymmetrically from one side of a growing point, resulting in deflected rather than bifurcated growth.

References

{{Taxonbar, from=Q3517423 Teloschistales Lichen species Lichens described in 1788 Lichens of Africa Lichens of Asia Lichens of Europe Lichens of North America Lichens of Oceania Lichens of South America Taxa named by Olof Swartz