Talk:Lichen

Plural

I always thought the plural was simply "lichen", but shouldn't this be at the singular anyway? Tokerboy — Preceding undated comment added 01:06, 22 January 2003 (UTC)

I'm sure there is some linguistic reason why we want the plural to be "lichen" -- it's a common mistake. But the plural is "lichens." Psora 20:08, 23 January 2006 (UTC)

We want the plural to be lichen because lichen is made up of multiple organisms, so it makes sense to call it lichen as a plural, I was recently doing this in a Biology class, and wrongly corrected my teacher (whoops) — Preceding unsigned comment added by JhePittsStop (talk • contribs) 21:55, 11 November 2015 (UTC)

We in Italy say lichene and licheni (plural). All the English dictionaries I have consulted have the regular plural form for lichen. Probably because we refer with this term at the single agglomeration of papules. Your reasoning is good but pheraphs the scientific dictionary is divergent from the English dictionary, as in some cases. Ivanmellace (talk) 21:28, 15 November 2023 (UTC)

Picture arrangement

You may have noticed that it seldom works out very well to have lots of pictures evenly registered along one side, as that sort of sets the amount of text that needs to be present in each section. I like all the pictures, but arrangementg with some on the bottom may be a better arrangement. - Marshman 06:01, 2 March 2006 (UTC)

Yeah, lots of pictures here.--HisSpaceResearch 09:48, 8 February 2007 (UTC)

Either a gallery can be added or some will have to go, but it is a bit much they way it is now. 130.216.191.182 06:07, 19 March 2007 (UTC)

I've moved all but a few of the pictures to a photo gallery at the bottom of the article, and placed the remaining ones in pertinent sections. If you can place the gallery in a better position (I'm not sure what the convention is), then please do so. --MithrandirMage 03:12, 20 March 2007 (UTC)

The article has had many modifications of images since the above discussion. I propose a gallery of 4 images, adjacent to the lead, showing clear examples of crustose, fruiticose, foliose, and squamulose growth forms. FloraWilde (talk) 12:36, 20 September 2014 (UTC)

examples?

Would someone be kind enough to provide a short list of common lichens with the taxonomy of their component fungi and algae? Such as reindeer moss and Iceland moss and Wolf moss and so forth? Or links if this is more practical? NaySay 15:42, 5 September 2006 (UTC)

There certainly should come some lists of lichens... It is however extremely hard to compile a list of common lichens for a very simple reason: lichens common in Brazil are not common in England, lichens common in Australia are not common in USA etc! And second, such list would become far too long (if not extremely subjective) to put into this general article... So far, please see Category:Lichens for the currently existing articles. Kaarel 19:15, 5 September 2006 (UTC)

That needn't be an issue. This is English Wiki, so providing examples which might be accessible to most English-speakers--England, USA, Canada, Australia, New Zealand--would be a good start. For example, Reindeer moss, which is certainly well known in many locales. And there are lichens which have relatively greater economic importance, such as oakmoss (used in perfumery and found throughout the Northern hemisphere) or reindeer lichen (which is used for food.)NaySay 15:14, 4 October 2007 (UTC)

Mention of Reindeer Moss was added to the lead 1st paragraph. FloraWilde (talk) 12:41, 20 September 2014 (UTC)

Brown algae & yellow-green algae as phycobionts

A paragraph was added saying some lichens have brown algae and yellow-green algal as phycobionts. Which lichens? Where is the reference?Heliocybe 18:46, 30 May 2007 (UTC)

Many photobionts have been proposed in a rather speculative manor (e.g. [1]). However, if you think these claims are unsupported, please feel free to boldly change the article. It could use it. Thanks, Wachholder 06:14, 31 May 2007 (UTC)

Lichen Speed of Growth

I know lichens are very slow growing, but how slow? I'd like to see information on the relative speed of growth as it varies with type and climate. BeeTea 03:07, 19 June 2007 (UTC)

According to Mason Hale, Bulletin of the Torrey Botanical Club, Vol. 86, No. 2 (Mar. - Apr., 1959), pp. 126-129 (doi:10.2307/2482993), "the foliose species Parmelia isidiata has grown regularly at the rate of 1.6 mm. per year in radius," while "crustose species increased in radius from .33 to 1.4 mm. per year." This was in Connecticut. Fruticose lichens can grow quite a bit faster. I too would like to see an extensive review of the biogeography of lichen growth rates. See here and here if you want to get started on that. Thanks! Wachholder 09:28, 19 June 2007 (UTC)

Form and Morphology

Aren't "form" and "morphology" redundant? Also I don't think the third paragraph, possible parasitism relates to this topic; it could be consolidated with the mention of the same thing in the first section. --Ericjs 03:13, 4 July 2007 (UTC)

Proposed image of lichen at gull colony

Gull colony with Caloplaca and/or Xanthoria (Teloschistaceae). The lichens are the orange areas. The white areas are bird droppings.

Hi, I was wondering if it could be useful to illustrate this article with this image? -- Slaunger (talk) 13:06, 13 March 2008 (UTC)

I would argue against using this image, as it could confuse the viewer as both lichens and bird droppings are pictured (requiring a special comment in the description). The existing images of lichens are fine. Your image has found a good use in the Greenland article. -- MightyWarrior (talk) 11:33, 14 April 2008 (UTC)

OK. Thank you for taking to time to consider it and comment on it. Personally I find it interesting with the Xanthoria and/or Caloplaca specialized to the nutritious environment. But perhaps this would be more relevant in s more specialized contaxt dealing with those lichen families and/or deling with lichen adapted to special environments. -- Slaunger (talk) 11:49, 14 April 2008 (UTC)

Pronounciation

I am not a native speaker of English, so I looked up the word's pronunciation and while this page says it's /laɪ.kən/, my Cambridge Dictionary says it's /lɪtʃ.ən/, also saying that /laɪ.kən/ is American way of saying it? Is this true? 84.50.228.110 (talk) 20:00, 18 April 2008 (UTC)

I've heard both pronunciations in the UK; I'm not aware of one or the other predominanting or being considered to be more Britsish or American. My advice: use whichever you feel most comfortable with; you'll be understood. -- Timberframe (talk) 13:18, 15 May 2009 (UTC)

Seems like we aught to have some kind of guide here, even if that guide gives two different pronunciation schemes. At Dictionary.com I am seeing /laɪ.kən/; Wiktionary gives both, specifying that /lɪtʃ.ən/ is a UK pronunciation. I am going to try adding the IPAc-en template to give both ways of pronouncing it. A loose noose (talk) 05:42, 28 July 2018 (UTC)

The online OED cites only /laɪ.kən/, though curiously, Oxford Living Dictionaries also cites /lɪtʃ.ən/. OED, as a descriptive and not prescriptive dictionary, seems in error. Incidentally I'm not convinced The Spectator, a political magazine, is a reliable source for this topic. Hairy Dude (talk) 14:27, 10 January 2019 (UTC)

Coxson 1990

Please add the appropriate reference.Heliocybe (talk) 19:08, 15 May 2008 (UTC)

I came here to ask the same question. "the work of Coxson (see above) mutualism would appear to best summarise our current knowledge." If this is the case, we need to have the ref. If not, this is POV and needs to be removed or balanced. Also, a couple of additional related points:

• "There is evidence to suggest that the lichen symbiosis is parasitic rather than mutualistic (Ahmadjian 1993). However, this now needs to be re-examined in light of Coxons (sp?) work." Ahmadjian's cited work from 1993 needs to be re-examined in light of a 1990 publication? I suspect Ahmadjian might disagree with that!
• The lead section is now WAY too long, see Wikipedia:Lead section. It's supposed to be "a short, independent summary of the important aspects of the article's topic," not a detailed academic discussion on the pros and cons of current hypotheses.

I know almost nothing about this topic. Can a biologist please fix this problem? Thanks, Walkerma (talk) 18:09, 7 July 2008 (UTC)

Tone, use more plain English

This article seems, in parts, to be written in an academic obscurantist style which is pretty jarring from Wikipedia's usual casual English style. Phrases like "the mutalistic “marriage” slowly became constant" are ridiculously overbaked for example. Other sections use technical buzzwords in places where common words would be clearer. 82.16.16.210 (talk) 15:24, 1 October 2008 (UTC)

I tried to move all nonessential technical terms and from the lead, and define all essential technical terms with plain English. The article body still needs similar work, and needs to be organized so that one section flows to the next, yet can be read in isolation, by briefly redefining technical terms as they are reintroduced in each section. FloraWilde (talk) 12:56, 20 September 2014 (UTC)

Is there a way to add keywords somewhere in an article? e.g. I'd like to add "fungus hybrid" and "fungi hybrid" and "algae hybrid" (and alga and algal) as keywords so searches (in here or on search engines) of those terms will find the Lichen article, but I don't see an obvious way to add keywords without adding those phrases to the articles themselves. They're more-properly a symbiosis, but "hybrid" is not incorrect, either. Darr247 (talk) 06:28, 14 July 2018 (UTC)

Article improvement

I'd like to take a stab at improving this important article to WP:GA status. Some major reorganization is needed, as well as much additional material. If anyone has ideas on how to improve the article, please drop a note here at the talk page, or just be bold and edit the main page. I'm not a lichen expert, just a guy with a big stack of books. I also rerated the WikiProject Fungi template from B to C; needs to be better cited for B class. Sasata (talk) 17:27, 31 January 2009 (UTC)

Not my subject either but I've made a start by standardising ref formats. -- Timberframe (talk) 13:20, 15 May 2009 (UTC)

Bot-generated content

A computerised algorithm has generated a version of this page using data obtained from AlgaeBase. You may be able to incorporate elements into the current article. Alternatively, it may be appropriate to create a new page at Lichen (alga). Anybot (contact operator) 17:15, 21 February 2009 (UTC)

Missing content from article

So how did biologists learn that lichens were composite organisms? Or was this fact known since antiquity? (I seriously doubt that, based on what I've read of Pliny's Natural History, but it's possible.) -- llywrch (talk) 17:19, 13 August 2009 (UTC)

Several different people began to propose this in the late 1800s, including the famous author Beatrix Potter, but it took a while for their views to become accepted by the scientific community. Millifolium (talk) 23:22, 4 March 2010 (UTC)

Now that Toby Spribille (University of Graz) and team has shown that lichens are composed of three elements ascomycete + basidiomycete + algae, I believe this needs to be added to the the content. J.P. (2016): Basidiomycete yeasts in the cortex of ascomycete macrolichens. Science DOI: 10.1126/science.aaf8287​ — Preceding unsigned comment added by Hollisterbulldawg2 (talk • contribs) 14:14, 24 July 2016 (UTC)

Question

I was looking for something about Lichen in the wiki about what they eat/(energy sources) and by products. anyone one have an idea? —Preceding unsigned comment added by 151.193.213.25 (talk) 10:18, 16 December 2009 (UTC)

Taxobox?

I was just wondering why no taxobox is incorparated? I understand that a lichen is really two species, although shouldn't at least the fungus be represented, especially in the light of fungi interchanging algal symbionts.Mike of Wikiworld (talk) 17:19, 5 May 2010 (UTC)

The fungal and algal species in the lichen are highly variable coming even from different kingdoms. de Bivort 17:49, 5 May 2010 (UTC)

There is a taxobox in the taxonomy and classification section. Perhaps it should be moved to the end of the article? Millifolium (talk) 21:16, 11 May 2010 (UTC)

Ediacaran Lichens

Debivort's recent (6 June 2011) edit reversion has (perhaps as an oversight) ignored the fact that, assuming that reverted editor "Retallack" is the same "G.J. Retallack" who authored the paper in question, then there is no better qualified person to judge whether or not "... this claim ... has since been retracted by its author" - it is a bit hard to describe an edit as "uncited" when it is editing a citation of a valid publication by the editor themself.

On reading the paper, it seems to present a reasonable case for at least one Ediacaran organism (Dickinsonia) being either a fungus or a lichenised fungus, but does not offer a strong argument to resolve these possibilities. If (the editor) Retallak were to modify his edit to recognise this weaker claim, I would see no problem with it. FredV (talk) 15:48, 6 June 2011 (UTC)

Indeed, I did not notice that the username matched the reference. However, the reversion was reasonable. First, it was an uncited change. Can the identical reference cannot cite both retraction by the author and supportive evidence? Second, usernames can be made up willy nilly. Third, the lack of edit summary and single article focus of the user's edits suggests a single purpose account which should be scrutinized. That said - the Alcheringa 2007 article does indeed support the idea of a lichenous Dickensonia. Was this the article that was retracted? If so, what is the new evidence? de Bivort 17:17, 6 June 2011 (UTC)

A little detective work reveals the following:

04 Feb 08: User Smith609 first introduces reference to Retallack[2004] and asserts author's retraction in Retallack[2007]

11 Dec 09: User Retallack removes assertion about author's retraction

16 Feb 10: User Sasata merges "evolution" and "paleontology" sections, and reinserts assertion of author's retraction

04 Jun 11: User Retallack (again) removes assertion about author's retraction

06 Jun 11: User Debivort reverts Retallack's edit

It seems to me that this whole sequence rests on Smith609's mistaken assertion that Retallack[2007] was a retraction of Retallack[2004]; User Retallack has repeatedly pointed out that this is not the case (and, having read the paper, I agree with him/her). It really doesn't matter whether or not user Retallack is the author of the paper - although I think it most likely that he is. In either case, what other authority could he cite - he is simply correcting an erroneous claim regarding the content of the Retallack[2007] paper. Unless someone produces a convincing response to this argument, I shall restore user Retallack's edit (with a reference to this talk thread in the edit summary). For what it is worth, I assure all readers that I have no personal interest or involvement in this issue. FredV (talk) 09:08, 7 June 2011 (UTC)

Nice detective work. I support your actions. de Bivort 17:16, 7 June 2011 (UTC)

Just a humorous aside

So, fungi invented farming long before we did! Huw Powell (talk) 00:39, 12 August 2012 (UTC)

An omission

Was not Beatrix Potter (of Peter Rabbit fame) to first to claim that lichens are composite organisms? Why is she not recognized in this article. Her idea was unjustly rejected by her male peers; why is this injustice perpetuated in Wikipedia? 152.16.27.140 (talk) 21:30, 23 April 2014 (UTC)BWA

That is a very interesting point 152.16.27.140, why do you back away from it? There is a historical record to that effect which is of encyclopedic interest, and would be of value to this article if you can find the sources to back the information up. Plantsurfer (talk) 22:32, 23 April 2014 (UTC)

Is Haeckel suitable as lead image?

Resolved

I'm not convinced the Haeckel image is the right one for the lead. He has emphasized the symmetry of the specimens, and as with many of his marine illustrations, probably greatly exaggerated: I've never seen lichens quite like that. Would it perhaps not be better to put his 'artistic' image down in a History section, and to use the next image (which is already very large) as the sole lead image? Chiswick Chap (talk) 13:14, 22 May 2014 (UTC)

Yes, I agree. His images don't represent the natural appearance of lichens. Plantsurfer (talk) 21:42, 22 May 2014 (UTC)

Ok, I'll rearrange the images. Chiswick Chap (talk) 08:29, 23 May 2014 (UTC)

Are lichens carbon neutral?

Our article says "The algal or cyanobacterial cells are photosynthetic, and as in plants they reduce atmospheric carbon dioxide into organic carbon sugars to feed both symbionts." Here, "reduce" refers to redox. Presumably the fungal component does the opposite. Does anyone know a source on the overall carbon input/output for any lichen species, or for lichens in general? FloraWilde (talk) 12:38, 14 September 2014 (UTC)

A quick look on JSTOR reveals plenty of work of that kind. One might say that given that lichens grow, there must be a carbon balance ... but there are plenty of figures to prove that. For example, Upland Tundra in the Foothills of the Brooks Range, Alaska, U.S.A.: Lichen Long-Term Photosynthetic CO2 Uptake and Net Carbon Gain. Otto L. Lange, Sabine C. Hahn, Angelika Meyer and John D. Tenhunen. Arctic and Alpine Research, Vol. 30, No. 3 (Aug., 1998), pp. 252-261 has figures for (photosynthetic) Carbon uptake and net Carbon gain (after subtracting Carbon lost to respiration). For instance, Peltigera malacea, the fastest growing of the seven lichen species measured, took up about 4.5 mg of Carbon per gram of Carbon in the thallus in 19 days, and had a net Carbon gain of about 2.5 mg/g in the same period. Chiswick Chap (talk) 13:59, 14 September 2014 (UTC)

Thanks. One might actually say that given that lichens grow, and that they are not parasitic, there must be a carbon gain (not balance). I did not carefully look at the source you cited, but I assume it was written with a presumption that the lichens studied were not parasitic on some other life-form from which they might have gained carbon, in addition to uptake from the atmosphere. FloraWilde (talk) 13:50, 15 September 2014 (UTC)

Are the expression "lichenized fungus" and "lichen" synonymous?

Is there a RS clear authority as to whether "lichenized fungus" refers to the entire lichen[2], or just to the fungal component? FloraWilde (talk) 14:50, 14 September 2014 (UTC)

I think you've answered your own question with your ref, which like all the others treats the new term lichenized fungus as a synonym for the older term lichen, including its algal components. Chiswick Chap (talk) 15:04, 14 September 2014 (UTC)

Thanks. My question arises from what appears to be a usage in some authoritative sources that implies the expressions are not synonymous, and in others that the expressions are synonymous.

• Page 94 of Brodo, Sharnoff, and Sharnoff's Lichens of North America says (According to Lynn Margulis and Eva Barreno,[3]), “Every recognizable lichen is derived from a different species of lichenized fungus”. If the expressions were synonymous, this sentence would be a tautology (i.e., "Every recognizable lichen is derived from a different species of lichen"). So the expressions must not be synonymous for Brodo, Sharnoff, and Sharnoff.
• Sometimes the same source implies the expressions are not synonymous on one page, then that they are synonymous on another. For example, the sentence "Lichens (sometimes referred to as lichenized fungi) are classified with the fungi" implies that "lichenized fungi" is synonymous with "lichen". The similar sentences "Lichens are classified with the fungi (sometimes referred to as lichenized fungi)" implies that "lichenized fungi" refers to the fungal component, and the two expressions are not synonymous. The latter "not synonymous" sentence is quoted from the Australian Botanical Garden website page What is a lichen?. Yet at the same website, on the "What is not a lichen page, explicitly says the expressions are synonymous - "a lichen (also called a lichenized fungus)".

Brodo, Sharnoff, and Sharnoff is about as authoritative a source as it gets for Wikipedia, and would support adding a sentence to our article - "A lichenized fungus is the fungal component when it is living in association with the photosyhthetic component." But I would rather do an edit that says the opposite, "lichens are sometimes referred to as 'lichenized fungi'". FloraWilde (talk) 14:07, 15 September 2014 (UTC)

A lichen is always a lichenised fungus. A lichenised fungus is always part of a lichen. There are no exceptions. However, one term is referring to the whole thing, and the other to only one of the partners. A fungus that can form mutualistic associations with algae that qualify as lichens may not always do so, but much more commonly vice versa. A fungus may form stable associations with algae in which it is not the external partner, but then it is not recognised as a lichen (Hawksworth 1988). Dobson 2011 also notes that name of each lichen species can only be applied to the fungus, that each species has a different fungus, but the same algal partner (e.g. Trentepohlia) may occur in many different lichens. Plantsurfer (talk) 15:29, 15 September 2014 (UTC)

I expect you are right, but in that case there are plenty of publications that should have been RS but which get it "wrong": in other words, both usages exist, and could easily be about equally common, worse luck. Chiswick Chap (talk) 15:56, 15 September 2014 (UTC)

Before today, I thought like Plantsurfer - a lichenized fungus is a fungus that is part of a bigger whole, and no naturally found apart from that whole - "the fungi that form lichens do not occur in nature as independent organisms, a number of the photobionts can be found in free-living forms. It is possible to separately culture the two partners in the laboratory...".What is a lichen? But the three sourced definitions are cited here say,

"Lichenized fungi (sic fungus) - definitions -

A. Hawksworth: A stable self-supporting association of a mycobiont and a photobiont in which the mycobiont is the exhabitant.

B. Ahmadjian: An association between a fungus, usually an ascomycete but in a few cases a basidiomycete or deuteromycete, and one or more photosynthetic partners, generally green algae or cyanobacteria. In all lichens the fungus forms a thallus or lichenized stroma that may contain unique secondary compounds.

C. McCune: An obligate mutualistic relationship between a fungus and a photosynthetic partner.

The first two definitions say a lichenized fungus is an association or relationship, not the fungus in that association or relationship. Chiswick Chap is right about "wrong". FloraWilde (talk) 23:41, 15 September 2014 (UTC)

OK, this is a pointless argument about semantics. You might consider a recent paper Buckley HL, Rafat A, Ridden JD, Cruickshank RH, Ridgway HJ, Paterson AM. (2014) Phylogenetic congruence of lichenised fungi and algae is affected by spatial scale and taxonomic diversity. PeerJ 2:e573 http://dx.doi.org/10.7717/peerj.573 in which they also talk about "lichenised algae". It is a no-brainer that since a lichen is an association of a fungus and an alga, any discussion of each partner separately will need to use terms such as "lichenised alga" or "lichenised fungus". Plantsurfer (talk) 08:35, 16 September 2014 (UTC)

I think this isn't so much a matter of semantics as a matter of rhetoric. Synecdoche (referring to the whole by a part) is very common in language generally, so much so that we usually don't notice it, and in this case it certainly doesn't reflect any disagreement over what a lichen or a lichenized fungus actually is. Rather the synecdoche reflects a view that the classification of lichens should be based on the fungal partner rather than treating lichens as a distinct taxon in their own right. Thus on one view the whole entity is classified as a lichenized fungus rather than a combined organism, so the important part in this view, the lichenized fungus, is used to stand for the whole. Not surprisingly, a quick search through the issues of the British Lichen Society Bulletin I happen to have doesn't show a single use of "lichenized fungus", since the Society is devoted to lichens as a taxon distinct from fungi (they are lichenologists, not mycologists interested in lichenized fungi). Peter coxhead (talk) 09:07, 16 September 2014 (UTC)

This seems at first glance like a pointless, nitpicking discussion, but let me add one nit I have not seen picked. People for years have been applying scientific names to lichens, much as if they were a distinct group comparable to cycads or bryophytes. Question is to what does the scientific name apply? Does it apply to the fungus? To the alga? To the association of the two? One might argue that there should be three names involved here: one for the fungus, one for the alga, and one for the symbiotic pair. But no, the decision was made some time ago the the name that has been applied to the symbiotic lichen is also the name of the fungus. Each lichen has a distinct fungus, but the alga in one lichen is frequently indistinguishable from the alga in another lichen. This enables you to decide which herbarium cabinet to put the specimens in, and where to put the lichen on a phylogenetic tree.Joseph Laferriere (talk) 13:46, 16 September 2014 (UTC)

However, the strict cladists don't like this approach (keeping lichens as a separate taxon), and you'll find more and more classifications which put lichens in various places among the fungi. See this for example. That's why I think there's a rhetorical purpose in calling a lichen a lichenized fungus. Peter coxhead (talk) 18:54, 16 September 2014 (UTC)

I made this unsourced edit[4]. FloraWilde (talk) 03:14, 17 September 2014 (UTC)

Here is an article that discusses the problem of this section, in plain English - [Form and structure - Sticta and 'Dendriscocaulon'. Note the scare quotes around the second genus in the title, but not around the first. (Thanks Plantsurfer, for finding these genus names. See discussion at talk page section immediately following.) FloraWilde (talk) 13:44, 17 September 2014 (UTC)

What is the fungus that is lichenized by two photobionts at different times? Is there just one species name?

(This section is related to the section above.) I recently read there is a fungus (not named in the article) that is lichenized by two different photobionts (both algae, as I recall), but not at the same time, thereby creating what would be two entirely different lichens, except for the classification scheme of defaulting to the fungus. Does anyone know what the fungus is, and how the two different lichens are classified as being different? — Preceding unsigned comment added by FloraWilde (talk • contribs) 22:41, 16 September 2014 (UTC)

There are many examples of lichens with alternative photobionts. Not sure which is the one you have in mind. For example Lobaria photobionts are Trebouxia, Myrmecia or cyanobacteria Nostoc and Scytonema. Nephroma use green alga Coccomyxa or cyanobacterium Nostoc. Psoroma use photobiont Myrmecia, but external cephalopodia contain Nostoc. Plantsurfer (talk) 00:18, 17 September 2014 (UTC)

Thanks, Plantsurfer. That was just the answer I was looking for in order to raise my underlying question using sources. The Lobaria article in Flora of Australia volume 58A (2001)) says,[5] "Photobiont a green alga (Myrmecia or Trebouxia) or a cyanobacterium (Nostoc or Scytonema); in those species with a green photobiont, internal and/or external cephalodia containing a cyanobacterial photobiont normally present..." Is there a single lichenized fungal species that is then named as a different lichen species for each association with different photobionts, or are there different species of fungus, all in a single genus, then each different species gets lichenized by different photobionts? FloraWilde (talk) 00:35, 17 September 2014 (UTC)

Dobson 2011 (ISBN 9780855463131) says this about Lobaria amplissima: "Large, mature specimens (up to 1 m wide) sometimes have brown-black, coralloid outgrowths (cephalopodia) up to 2cm wide containing a blue-green photobiont." and "These outgrowths can break off and continue an independent existence and are called Dendriscocaulon umhausense". Incidentally, Myrmecia points to an ant on WP, not to an alga. This needs fixing.Plantsurfer (talk) 09:29, 17 September 2014 (UTC)

@Plantsurfer, Myrmecia (disambiguation) and Myrmecia (algae) stub started. FloraWilde (talk) 12:36, 17 September 2014 (UTC)

@Plantsurfer - Thanks, you named the exact species that I recently read about, but could not recall where, or what species. There is a Plain English discussion of the naming problem in this article titled - Sticta and 'Dendriscocaulon'. Note that the title of the article has scare quotes around Dendriscocaulon, but not around Sticta. FloraWilde (talk) 13:40, 17 September 2014 (UTC)

Please help write taxobox for the "genus with scare quotes" - Dendriscocaulon

The "lichenized fungus", Dendriscocaulon, is a genus of several different species by all measures other than the convention of classifying lichens by their fungal component, which is the only thing going. Please contribute to this article that does not neatly fit into the WP:Plant article template, and does not fit a taxobox into it very neatly. FloraWilde (talk) 14:46, 17 September 2014 (UTC)

Well, if we follow the modern convention of classifying "lichens" as "lichenized fungi", then it seems to me that Dendriscocaulon should not have a taxobox; Dendriscocaulon is 'really' Sticta. The situation seems analogous to "form taxa" in paleobotany, or the separate names given to fossil gametophytes and sporophytes before their true identity was discovered (e.g. the gametophyte of Rhynia gwynne-vaughanii was called Remyophyton delicatum). Of course this takes a position on classification that I know that at least some lichenologists don't accept, but as we've discussed before, taxoboxes by their nature are not suited to presenting alternative classifications. Anyway, Plantsurfer seems to be something of an expert in this area, so I'm happy to go along with whatever his view is. Peter coxhead (talk) 16:31, 17 September 2014 (UTC)

Plantsurfer seems to have expertise in many areas, and applies that expertise to make many good edits. Rerding your scare quotes around 'really', I just commented to Sminthopsis84 at the Dendriscocaulon article talk page that the current 'reality' of lichen classification conventions (which appear to sometimes come from 'above', not within the lichenologist community) is like classifying humans by a bacteria that has been in everyone's intestine so far, then discovering an isolated tribe of people without the bacteria, and calling them a different species... only because of classification conventions. I posted a link to this discussion at the talk page of species problem, which might provide editors who have different perspectives than strict WP:Plant project editors. FloraWilde (talk) 16:48, 17 September 2014 (UTC)

Are all lichens poikilohydric?

Our article says, with RS, "Lichens are capable of surviving extremely low levels of water content (poikilohydric)." This sentence is easy to source with other RS. But is there an actual authority, other than summary descriptions used as RS, that concludes all lichens are poikilohydric? FloraWilde (talk) 13:30, 17 September 2014 (UTC)

Help with plain English characters for /ˈlɪtʃən/

The article starts off "A lichen (/ˈlaɪkən/, sometimes /ˈlɪtʃən/ ..." The characters used in a pronunciation guide can, and should, be intelligible to an elementary school student. Can anyone help fix this by use of more common special characters for pronunciation? FloraWilde (talk) 14:31, 18 September 2014 (UTC)

@FloraWilde: it's not "resolved" because it only gave one of the pronunciations of the word – the one with a hard "k" (which I use myself, but which in my experience isn't the most common among British lay people). The alternative, represented by /ˈlɪtʃən/, uses the soft "ch" with a short "i". Because of the ambiguity of English orthography, this can only be represented by the IPA in my view. See Wikipedia:Manual of Style/Pronunciation which explicitly says that IPA should be used. I've restored the original; by all means add other guides but don't remove this one. Peter coxhead (talk) 07:58, 25 September 2014 (UTC)

I took down the resolved tag. I assumed that general public English language dictionaries existed with pronunciations of common words like "kitchen", although I never looked until just now, and discovered that online dictionaries are very different than those used in American public schools (or at least used to be used). I just tested "/ˈlaɪkən/, sometimes /ˈlɪtʃən/" out on the staff here at a US Starbucks, and no one could read it. I explained to them that "ə" was a mathematics-speak for "such that" , and "ʃ" for an abstraction of "summation", like in calculus and analysis, and they all nodded as if understanding. The "ʃ" also appears in an old book I happen to have on me, and which also appears online here. The lichen article talk page is probably not a good place for me to be "bitchin" about (possibly unavoidable) plain English deficiencies in Wikipedia:Manual of Style/Pronunciation (which I have not read). I found two RS for this edit, "In the US it is commonly pronounced like in 'like in', and in UK it rhymes with kitchen", so the staff at my Starbucks could communicate with their British counterparts. But the article lead is already overlong and I intend to prune it back after I finish adding more content, reorganizing, and making the main articles referred to in the section, more than just copies of the sections. FloraWilde (talk) 11:58, 25 September 2014 (UTC)

I started a discussion on use of esoteric character at the beginning of an article, citing lichen as an example, at WP:PRON[6]. Hopefully they will not next be issuing guidelines on pronouncing bionomial names, which of course should always be as with a thick California accent. (Meaning Baja California, of course.) FloraWilde (talk) 13:57, 25 September 2014 (UTC)

I can read IPA because I taught computational linguistics, but I know how difficult students found it to learn, so I'm not enthusiastic about its use in the lead section. However, the problem is that alternatives are very hard to get right. /ˈlaɪkən/ is not the same as "like in", which is more likely to be pronounced /ˈlaɪkɪn/, but rather "liken" as in "I liken X to Y". Peter coxhead (talk) 14:25, 25 September 2014 (UTC)

The only real solution would be audio clips that the reader (listener) can click, recorded by professional "pronouncers". I think that will eventually happen. For now, IPA is a small waste of space for almost all readers, including me. That said, there are far worse things in Wikipedia than small wastes of space. ‑‑Mandruss (talk) 01:45, 26 September 2014 (UTC)

I'm sure you're right on both counts, but don't underestimate the number of such clips that would be needed to keep everyone happy, given the considerable variation in pronunciation among speakers of different English dialects, and given the passion that this variation seems to arouse (as an example, consider "herb", "herbaceous", etc., where those who don't pronounce the "h" and those who do regularly edit-war over "an" versus "a"). Peter coxhead (talk) 07:26, 26 September 2014 (UTC)

Construction tag - Plain English rewrite of lead, nonessential technical terms/content moved to relevant sections

I put up a construction tag. I am doing a Plain English rewrite of the lead. Any essential technical term is defined in plain English followed by the technical term in parentheses, and any nonessential technical term has been moved to a section below. I will similarly start each section with plain English definitions, and move from this to technical info and terms per MOS. When I am done with the sections, I will go back to the article history and check each sentence had its content and sources preserved, so if you notice content was accidentally deleted, it will get restored (or you can stick it back in). FloraWilde (talk) 14:56, 19 September 2014 (UTC)

Pseudotrebouxia

• The current UC Berkeley Museum of Paleontolgy website says, "The algal partner is usually... Trebouxia, Pseudotrebouxia, or Myrmecia". The U of Omaha website has "Pseudotrebouxia was split from Trebouxia in the late 1970’s based on apparent differences in cell division patterns. However, recent studies do not support the recognition of two genera." These sources are inconsistent. Does anyone know why? FloraWilde (talk) 00:37, 22 September 2014 (UTC)

Trentepohlia plus Trebouxia and Asterochloris is over 75% ?

• The UK Natural History Museum website says "Trentepohlia is the most common algal genus in lichen."[7] Our article says "Trebouxia occurrs in about 40% of all lichens." without a reference, but is supported by an Environmental Microbiology article saying "Trebouxia and Asterochloris occur in at least 35% of all lichens".[8] This implies that Trentepohlia plus Trebouxia and Asterochloris is over 75% of the species. If that were true, then it seems this fact would be popping up in at least one of the many articles I have recently read. Does anyone with expertise know what is up, like a recent reclassification causing numbers to change? FloraWilde (talk) 00:38, 22 September 2014 (UTC)

Toby Spribille's work

In non-technical articles (See here and here) it would appear that Toby Spribille et al have found that lichens are a combination of two fungi with an alga, or a fungus, a yeast and an alga, which runs counter to the accepted structure of a lichen. I see no mention of this in the article. I am no expert on the subject, but if this recent discovery has any validity, I would have thought it at least would rate a mention, as it would require a rewriting of the entire article. Ptilinopus (talk) 20:51, 21 July 2016 (UTC)

It will certainly need to be incorporated in the article. The source is an early release paper in Science (here) so as of now only available online in full to subscribers. As per WP:PSTS, we need to be careful in using single primary sources. Peter coxhead (talk) 05:52, 22 July 2016 (UTC)

A current reference is http://science.sciencemag.org/content/353/6298/488 — Preceding unsigned comment added by 65.130.4.64 (talk) 01:59, 10 July 2017‎ (UTC)

In the world of Wikipedia references trump reality. — Preceding unsigned comment added by 128.61.69.11 (talk) 10:09, 22 July 2016 (UTC)

I agree it is sensible to be cautious. Presumably, others will be soon trying to replicate, or challenge, so additional papers will soon be available.--S Philbrick(Talk) 15:51, 23 July 2016 (UTC)

I've dug around and it appears that Dr Spribille's work is starting to be cited in other papers (3 so far on Google Scholar). I have taken to monitoring this as a pet project. Manning (talk) 05:23, 1 November 2016 (UTC)

I came here from popular Spribille and feel a need for the definition of a lichen species, and also something, anything on component fungus and algae, such as how many species are there, 6? 1,000s? ...and some general characteristics if any...are they consequential, noticeable? I almost get the feeling different species ("kinds?") are defined by form. This seems basic enough, it should be in the lede section. Corals are often described as colonies, but not lichen? It's very confusing. — Preceding unsigned comment added by 2602:306:CFCE:1EE0:85EE:9A37:8644:8E90 (talk) 01:20, 3 November 2019 (UTC)

The current mention of the reference falsely represents the findings of Spribille 2016 10.1126/science.aaf8287. The findings indicate that the triple symbiosis is near a world wide norm rather than an occurrence found in a single species.

Considering the status as a primary research article I understand hesitation, but the current addition is simply incorrect. Perturbedxuuya (talk) 21:00, 29 February 2024 (UTC)

Sexual reproduction

In the sexual reproduction section of the article, the two paragraphs containing the word "pycnidia" contain material on asexual reproduction, yet the section on asexual reproduction does not mention pycnidia. Before the world is permanently led astray by this, would some energetic, brave soul please sort this out? --75.164.155.194 (talk) 19:34, 25 July 2016 (UTC)

Further reading

Removing section from article. We have 128 references employed in the article. This information is redundant at best per WP:NOTCATALOG. --Zefr (talk) 15:57, 26 June 2017 (UTC)

Further reading

• Gies, Erica (2017). "The Meaning of Lichen". Scientific American. 316 (6): 52–59. doi:10.1038/scientificamerican0617-52. PMID 28510551.
• Gilbert, O. 2004. The Lichen Hunters. The Book Guild Ltd. England.
• Haugan, Reidar; Timdal, Einar (1992). "Squamarina scopulorum (Lecanoraceae), a new lichen species from Norway". Nordic Journal of Botany. 12 (3): 357–360. doi:10.1111/j.1756-1051.1992.tb01314.x.
• Hawksworth, D. L. and Seaward, M. R. D. 1977. Lichenology in the British Isles 1568–1975 The Richmond Publishing Co. Ltd., 1977.
• Kershaw, K. A. Physiological Ecology of Lichens, 1985. Cambridge University Press Cambridge.
• Knowles M.C. (1929). "Lichens of Ireland". Proceedings of the Royal Irish Academy. 38: 1–32.
• Purvis, O. W., Coppins, B. J., Hawksworth, D. L., James, P. W. and Moore, D. M. (editors) 1992. The Lichen Flora of Great Britain and Ireland. Natural History Museum, London.
• Sanders W.B. (2001). "Lichens: interface between mycology and plant morphology". BioScience. 51 (12): 1025–1035. doi:10.1641/0006-3568(2001)051[1025:LTIBMA]2.0.CO;2.
• Seaward M. R. D. (1984). "Census Catalogue of Irish Lichens". Glasra. 8: 1–32.
• Whelan, P. 2011. Lichens of Ireland. The Collins Press, Cork, Ireland.

Importance? Quality?

This Talk page exhibits classic problems with Wikipedia. as a relative newcomer to editing, I frequently see these problems.

1. Too many templates, as soon as someone wants a new feature, they create a new template. There are five templates that assign Quality and Importance. The qualities currently assigned are: "B-class" and "C-class", there really should be only one quality ranking. Personally, I think Lichen is a solid B. The importance currently assigned are: "not yet rated", "Top", "High" and "level-4" (I assume this is an importance rating). It is easy for me to understand different importance for different projects.
2. Too many cooks. The unilateral removal of "Further Reading" because there is 128 references was not warranted. I agree five books/articles about Irish/British lichens is overkill, but at least one should have been kept. Also, "... a new lichen species from Norway" is too detailed. Also, I probably can unilaterally change the Quality. I assume (hope?) this is monitored.
3. I think I can make some improvements to the Lichen article, mostly copy edits and format, but I will probably step on some toes. A lot of editors don't really appreciate the "Be Bold" mantra.

User-duck (talk) 22:47, 30 August 2017 (UTC)

@User-duck: please note that the templates you are talking about are not meant to indicate an assessment of the article's importance and quality to Wikipedia but to the relevant WikiProjects. It's perfectly possible for an article to be of high importance to one WikiProject but not to another; e.g. the national flower of a country may be of high importance to the country WikiProject but of low importance to WikiProject Plants. The same can sometimes apply to quality. If I assess an article for WikiProject Plants, I compare it to the plant article template and the plants assessment criteria. Other WikiProjects may have different requirements. So you should not change quality assessments for a WikiProject unless and until you understand their processes and standards. Peter coxhead (talk) 08:43, 31 August 2017 (UTC)

Course assignment January-April 2022

This article was the subject of a Wiki Education Foundation-supported course assignment, between 5 January 2022 and 4 April 2022. Further details are available on the course page. Student editor(s): Babamachine (article contribs).

There is no study of the percentage of terrestrial surface covered in lichen. The 6-8% figure is a fabrication

Other editors have previously queried this issue below. The reason the citations cannot be found is that they are all circular and the original research does not exist. There is now a journal article in Bioscience about how the figure is not supported by any evidence, and that it has been widely repeated without being challenged: https://doi.org/10.1093/biosci/biae048

I am removing the 8% figure as a false factoid unsupported by any science. Tartan Nutter (talk) 08:52, 5 July 2024 (UTC)

Thank-you for excising the bogus "factoid" from this article only a day after the scientific publication came out debunking it! Wikipedia works, sometimes. Esculenta (talk) 23:43, 5 July 2024 (UTC)

Citation issues, percentage of terrestrial surface covered in lichen

In this article it cites the claim that 7% of the planets surface is covered in lichen, but the citation just goes to a new york time’s article that doesn’t cite an actual source. The assertion that 7% of the earth is covered in lichen is super common though and I keep finding it in other papers, but they all loop around to each other and I can’t find a primary source. Its kind of driving me crazy because this feels like a very falsifiable claim that should have a clear origination. 73.180.15.156 (talk) 07:10, 15 February 2023 (UTC)

A quick search found these, which both say lichens are the dominant life form over some 8% of the earth's surface:

• Viewpoint by Vernon Ahmadjian (one of the premier lichenologists of the last century) in Bioscience, 1995
• Article in Current Biology, Duke University

— Preceding unsigned comment added by MeegsC (talk • contribs) 13:19, 15 February 2023 (UTC)

No explanation of “composite organism”

The very first sentence of our article says:

A lichen is a composite organism…

Is this terminology standard? We don't have an article on composite organism, not even a redirect. I wanted to link it to some explanation but couldn't find anything anywhere.

Should we have an article titled “composite organism”? If this is terminology not explained elsewhere, we should explain it here, and shouldn't use it in the first sentence of the article.

—Mark Dominus (talk) 19:43, 20 December 2023 (UTC)

@Dominus:, you have to read the whole sentence. It finishes "that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship". That tells you right there that the lichen is an alga or cyanobacteria living within fungal filaments. Is that not clear? We at the (relatively) new lichen task force are in the process of completely rewriting the article (which is a bit of a mess at the moment) so it would be good to know what you're struggling with. MeegsC (talk) 22:50, 20 December 2023 (UTC)

I see, thanks. I thought that “composite organism” was a term of art with a specific meaning, and that perhaps there were other composite organisms that were not lichens. —Mark Dominus (talk) 01:30, 21 December 2023 (UTC)

I think (correct me if I'm wrong, licheners) that lichen is the only organism of its kind, thus why there is not an article about other things that are lichenous, because nothing else is a 3-part organism that we know of. Though technically some animals are really a composite organism since they host beneficial bacteria and fungi and worms and stuff... but I do not think that is called the same thing by scientists Andre🚐 23:28, 20 December 2023 (UTC)

lichen include a third component, a yeast

It has been years since the third member of the lichen symbiosis was discovered. I don't know how to fix this, but maybe someone will. https://www.purdue.edu/newsroom/releases/2016/Q3/yeast-emerges-as-hidden-third-partner-in-lichen-symbiosis.html#:~:text=%2D%20For%20nearly%20150%20years%2C%20lichens,or%20%22skin%22%20%2D%20yeast. 98.97.57.154 (talk) 22:26, 15 January 2024 (UTC)

Check out the "Physiology" section of this article, where this species interaction has been mentioned for years. Esculenta (talk) 22:47, 15 January 2024 (UTC)

the research is cited, as citation 1, but the text doesn't mention the yeast. Molly White has a YouTube about how to edit Wikipedia. This bothers me, too.maybe I will have time to log on tomorrow to try to fix it. 98.97.60.216 (talk) 05:22, 26 February 2024 (UTC)

I used Molly White's video to edit the very beginning of this, but it needs a re-write. It is full of references from before the discovery of the yeast, in 2016, and more recent research has revealed that some lichens include even more parts. I would like to remove the out of date references, but I don't know how, and a search comes up with nothing. Linddaski (talk) 04:14, 31 March 2024 (UTC)