Editing Lichenology (section)

===The beginnings===

Lichens as a group have received less attention in classical treatises on botany than other groups although the relationship between humans and some species has been documented from early times. Several species have appeared in the works of [[Dioscorides]], [[Pliny the Elder]] and [[Theophrastus]] although the studies are not very deep. During the first centuries of the modern age they were usually put forward as examples of [[spontaneous generation]] and their reproductive mechanisms were totally ignored.<ref>Lauder Lindsay, William (1856). ''A Popular History of British Lichens'' p. 22</ref> For centuries naturalists had included lichens in diverse groups until in the early 18th century a French researcher [[Joseph Pitton de Tournefort]] in his ''Institutiones Rei Herbariae'' grouped them into their own genus. He adopted the Latin term lichen, which had already been used by Pliny who had imported it from Theophrastus but up until then this term had not been widely employed.<ref>Lauder Lindsay, William (1856). ''A Popular History of British Lichens'' p. 23</ref> The original meaning of the Greek word λειχήν (leichen) was moss that in its turn derives from the Greek verb λείχω (liekho) to suck because of the great ability of these organisms to absorb water. In its original use the term signified [[mosses]], [[liverworts]] as well as [[lichens]]. Some forty years later [[Dillenius]] in his ''Historia Muscorum'' made the first division of the group created by Tournefort separating the sub-families [[Usnea]], Coralloides{{efn|"mostly [[Clavarieae]]", according to [[George Claridge Druce|Druce]].<ref>{{cite web |url=http://www.mobot.org/mobot/latindict/keyDetail.aspx?keyWord=coralloides |title=A Grammatical Dictionary of Botanical Latin: coralloides |first=P. M. |last=Eckel |website=[[Missouri Botanical Garden]] |date=2010–2021 |access-date=19 August 2021}}</ref>}} and [[Lichens]] in response to the morphological characteristics of the lichen [[thallus]].<ref>{{cite book |author=Joseph Pitton de Tournefort |title=Institutiones rei herbariae |language=la |trans-title=Institutions of botany |volume=1 |url=https://books.google.com/books?id=2BkOAAAAQAAJ&q=%22Tournefort%22+%22Institutiones+rei+Herbariae%22|year=1700 }}</ref>

After the revolution in [[taxonomy (biology)|taxonomy]] brought in by [[Carl Linnaeus|Linnaeus]] and his new system of classification lichens are retained in the [[Plant]] Kingdom forming a single group [[Lichen]] with eight divisions within the group according to the morphology of the [[thallus]].<ref>Lauder Lindsay, William (1856). ''A Popular History of British Lichens''. p. 24.</ref> The [[Taxonomy (biology)|taxonomy]] of lichens was first intensively investigated by the [[Sweden|Swedish]] botanist [[Erik Acharius]] (1757–1819), who is therefore sometimes named the "father of lichenology". Acharius was a student of [[Carl Linnaeus]]. Some of his more important works on the subject, which marked the beginning of lichenology as a discipline, are:

* ''Lichenographiae Suecia prodromus'' (1798)
* ''Methodus lichenum'' (1803)
* ''Lichenographia universalis'' (1810)
* ''Synopsis methodica lichenum'' (1814)
[[File:Flechte auf Fels.jpg|thumb|Lichen on rocks]]
[[File:Lichen foliacé2..JPG|thumb|[[Oakmoss]] (''Evernia prunastri'')]]

Later lichenologists include the American scientists [[Vernon Ahmadjian]] and [[Edward Tuckerman]] and the [[Russia]]n [[evolutionary biologist]] [[Konstantin Merezhkovsky]], as well as amateurs such as [[Louisa Collings]].

Over the years research shed new light into the nature of these organisms still classified as plants. A controversial issue surrounding lichens since the early 19th century is their reproduction. In these years a group of researchers faithful to the tenets of Linnaeus considered that lichens reproduced sexually and had sexual reproductive organs, as in other plants, independent of whether asexual reproduction also occurred. Other researchers only considered asexual reproduction by means of [[Propagules]].<ref>Lauder Lindsay, William. ''A Popular History of British Lichens''. p. 25.</ref>