Talk:Moss

Number of species

This page should say how many species of moss there are. --Savant13 14:01, 21 December 2006 (UTC) I <3 THE JO BROS! —Preceding unsigned comment added by 76.19.110.202 (talk) 20:16, 7 April 2009 (UTC)

On the north side?

Is it true that moss only grows on the north side of something, or is this a myth? It sounds false, because I can't think of a single aspect of nature that makes north special.

Bear in mind that I know nothing about mosses, but certainly in the northern hemisphere the north side of anything will get less light, and it does say in the article that mosses prefer low light situations. Maccoinnich 17:16, Mar 12, 2005 (UTC)

And this is why I don't understand why you guys can just add the information in without research on mosses that reflect this thought. I'm tagging this for expert needed cause you guys are obviously not experts so why should this info be included (without sources)? - M0rphzone (talk) 03:23, 31 October 2011 (UTC)

Indeed, in northern latitudes the north side of trees generally will have more moss on average than other sides. South of the equator the reverse is true. No Account

But why is this so? Have there been any studies on this? PeepP 13:48, 20 October 2005 (UTC)

The evidence points to this being a reproductive issue. The gametophyte generation in mosses, liverworts and ferns all require the presence of liquid water to allow the motile male gametes to reach the female gametes. In the absence of water no reproduction takes place. Hence the characteristic feature of most thriving communities of mosses, liverworts and ferns is that they live in wet or damp locations. The sunny sides of trees fail this test. There are of course always exceptions and some mosses are able to live in apparently very dry places but in all cases, careful study will reveal the presence of water at critical periods of the year. Velela 14:31, 20 October 2005 (UTC)

Please add this information to the article. PeepP 17:26, 21 October 2005 (UTC)

So I came to this article looking for more information on this because I was outside at work, and looked in the courtyard where there are several large stones. I noticed that moss was growing only on the north-side surfaces of these stones. The Courtyard is enclosed in all fours by tall buildings, so I don't think sunlight exposure is at work here. If you guys find more information regarding this please post. Taco325i 16:26, 7 April 2006 (UTC)

There are lots of possible reasons, including (1) people tend to sit preferentially on one side of the rocks, preventing moss from growing, (2) the rocks had moss on them when they were placed there and the moss was placed in that direction, (3) water tends to run down that side of the north side because of the slant of the rocks, and half a dozen other possibilities I could mention besides. Note that just because the buildings are tall doesn't mean that during important times of day or important times of the year that the sun doesn't preferentially hit the south side of the rocks. And of course, there's always the possibility that it's pure chance in this case. --EncycloPetey 02:44, 10 April 2006 (UTC)

I just happened to read the right section of the book "A Short History of Nearly Everything" by Bill Bryson. At the bottom of p. 427 you can find some info about that. According to him this applies to lichens and not mosses. --Emil Petkov 12:32, 6 October 2006 (UTC)

Whatever Mr Bryson has to say, the evidence is all around, certainly here in the wetter parts of northern Europe. Lichens, mosses and terrestrial coccoid green algae all visibly favour the northern sides of tree trunks. It doesn't require great science to demonstrate it, a walk in the woods is all that is required. Mt Bryson is amusing and erudite but I don't believe has made any claims to be a scientist, great or otherwise. I suggest that enjoying his text as amusing fiction but relying on competent observation and scientific method to determine the verifiable truths in biology may be the optimum balance. Velela 21:29, 6 October 2006 (UTC)

Is it really accurate to say that the northern side of things get more light? I mean, the sun is obviously 'pointed at' the equator, but it's so friggin huge that it might as well be 'overhead' no matter where you are. The idea that the northern side of the trees is 'wetter' by a significant degree sounds fishy

Why not read some ecology research? The northern side of objects in the northern hemisphere receive less light because of the curvature of the Earth. This feature of the Earth is also responsible for the seasons -- The angle of incident light varies seasonally. The sun is closer to being directly overhead (at noon) during the summer, but sits lower in the sky during winter. On a microclimate scale, it means that (on average) there is more shade on the north side of an object than on the south side. Bryophytes are known to prefer less intense and less direct light because of the problems of retaining water without a vascular system. See Bryophyte Ecology edited by Chopra and Kumra as one source with summary information about water relations in bryophytes. --EncycloPetey 01:03, 11 March 2007 (UTC)

I suggest you leave the city you have obviously been in your whole life, and enjoy nature for just a week-end. See a tree that is growing elsewhere than on a sidewalk. Come on ! How can anybody really believe that the north side of anything gets as much light as the south side ? Is the north side of your habitation as hot as the south side in summer at noon ? —The preceding unsigned comment was added by 81.56.208.127 (talk) 04:58, 22 April 2007 (UTC).

Let's be civil here. Unfortunately, just 'taking a look around' is only the start of research. I don't know about the northern hemisphere in general, but in my little corner of it, mosses and lichens both are not at all restricted to the north side of their substrates. Or to shady areas for that matter, I have moss in my lawn in full sun. We are far enough north here (Washington State) that the north sides of things get a lot of sun in summer. The sun rises in the north east, and sets in the north west, around the summer solstice. My north facing deck is in shade all winter but full sun in summer. There are other reasons proposed for why mosses grow where they grow. I suppose in most parts of the world, with drier sunnier weather than we get, it may be true that mosses GENERALLY grow on the north sides of their substrates. But it's just a generalization.Dog Walking Girl (talk) 15:32, 10 April 2011 (UTC)

Start it simpler

Um -- could we start a little simpler? This article doesn't really answer "What is moss?" unless you know an awful lot of botany to start with. (And the story about moss being on the north side of trees is said to have helped to make many people even more lost!) Oak 17:24, 04 November 2005

I agree that this article doesn't do a good job in the introduction of clarifying what a moss is for the non-specialist. Part of the problem is that in casual English, the word moss means "green scummy thing on a rock or tree". Many times, the word is applied to a liverwort, alga, or even to some bromeliads (Spanish "moss", a flowering plant) indiscriminately. To distinguish true moss (the subject of this article) from those other plants requires a level of technical description that can be very hard to bring down to the level or the casual reader. The required terminology just doesn't have an equivalent in casual speech. -- EncycloPetey 14:13, 5 November 2005 (UTC)

Dioicous vs dioecious

While dioecious is the correct spelling of that word (in both Commonwealth and American English), it is not the correct spelling for the word dioicous, which is another word entirely. In botany, a plant that is dioecious is a diploid sporophyte that produces either microsporangia or megasporangia, but not both on the same plant. A plant that is dioicous is a haploid gametophyte that produces either antheridia or archegonia, but not both on the same plant. So while seed plants may be either monecious or dioecious, they are all dioicous. Bryophytes produce only a single kind of sporangium, and so cannot be truly described as either monecious or dioecious. There are fundamental differences in the life cycle that necessitate a different vocabulary among bryologists. -- EncycloPetey 16:17, 6 November 2005 (UTC)

Image name is misleading

In the image at the start of the Classification section (captioned "three different types of mosses surround this tree trunk"), I can only see two species of moss. The box in the upper right shows a foliose lichen, which is a fungus-alga symbiosis. Also, the box on the left side of the image contains about half moss and half lichen. Does someone have a better image? -- EncycloPetey 16:25, 6 November 2005 (UTC)

A good source of images is always Wikimedia commons - see [Category:Bryophyta]

Velela 06:45, 7 November 2005 (UTC)

I looked, but that category of the Commons is empty. If I were in Arkansas or North Carolina, I'd just pop out and take a good picture to replace the current one. Unfortunately, the local climate is Mediterranean, which doesn't lend itself to finding good shots of mosses. -- EncycloPetey 13:20, 9 November 2005 (UTC)

You're right - sorry - no idea why that link didn't work . Try this one instead

http://commons.wikimedia.org/wiki/Category:Bryophyta.

There are hundreds of images to choose from. On a related topic, I have included a short plain man's guide to mosses at the beginning to overcome criticisms that this artcile was not suitable for non-botanists. I propose to do something similar for Liverworts and Hornworts. Any views ?

Velela 13:29, 9 November 2005 (UTC)

Since this issue covers more than one page, I'll respond on your talk page. -- EncycloPetey 13:55, 10 November 2005 (UTC)

GA review

While this article is pretty good, unfortunately it is almost completely unsourced, and the good article criteria stresses that all material in the article must be verifiable and cited. Once everything's cited, feel free to nominate this article again! Krimpet (talk/review) 02:01, 3 April 2007 (UTC)

Ant on moss image

This image was removed becuase it was a little blurry. Yes, it's blurry, but it's the only picture on the page that demonstrates the physical scale of moss. I would love to see a better picture, but until such a picture is available, it makes more sense to retain the information conveyed by the picture than to simply delete it for being less than ideal. --EncycloPetey 03:18, 4 April 2007 (UTC)

As per your request, I've made it part of my to-do list to take a shot of moss (perhaps 2-3 types if I can find them) with a ruler beside it. -- KirinX 05:56, 4 April 2007 (UTC)

Further to that, I still don't think that the image demonstrates scale to a definitive degree anyways, as ants come in many sizes (albeit all are fairly small, but so too can that be said for mosses -- I'm certainly unaware of any large mosses), and for the fact that there are two pictures of trees featuring different types of mosses on the stump or on the trunk of the trees. It's not unreasonable to believe people would have the same ease (or difficulty) in ascertaining scale from any of the pictures, closeups not included. In all honesty, I cannot see why you are defending the removal of this picture to the degree you are. Forgive my shortsightedness. -- KirinX 06:03, 4 April 2007 (UTC)

I agree, which type of ant is it? How big is the ant? How much moss is he standing on? I can't tell from that image, it tells me nothing about moss. ^High_InBC^{(Need help? Ask me)} 13:44, 4 April 2007 (UTC)

The picture could definitely be imporoved (and should!). I disagree with the arguments about moss on the sides of trees demonstrating scale, though. Some trees may trunks less than a half a foot in diameter, while others may have trunk bases over five feet in diameter (especially in tropical regions). I would have put in a replacement image long ago, but all my good moss images are on photographic slides and I have no way to scan them currently. --EncycloPetey 21:14, 4 April 2007 (UTC)

Moss leaves and stems

Bryologists do not put quotations around the word leaf. They do not call the leaves of mosses and leafy liverworts "leaf-like appendages"; they simply call them leaves. While mosses do not have "true" leaves, they do have leaves. Leaves have evolved multiple times in multiple linages. Even "true" leaves are not homologous among all groups, since the microphylls of lycophytes, the frond of ferns, and the leaves of seed plants all evolved independently of each other. Because of this, it is meaningless to say that mosses do not have "true" leaves, as if the presence of vascular tissue is something special. Denigrating the leaves of mosses is a POV issue perpetuated by botanists who do not study mosses. --EncycloPetey (talk) 19:08, 11 January 2008 (UTC)

Only just now did I find out about your wholesale reversion of my edits. I took this opinion straight from Biology 8th ed. (Raven), specifically page 587, which says,

...The gametophytes of mosses typically consist of small, leaflike structures (not true leaves, which contain vascular tissue) arranged spirally or alternately around a stemlike axis...

This means, in retrospect, that I probably should have cited it, but nevertheless my position was not unfounded. There is a bryologist in my biology department, so I might consult him on the subject, but there are nevertheless large differences between these structures (which might deserve mention in the article).

What I'm more concerned about is this: (diploid, i.e. each chromosome exists with a partner that contains the same genetic information). This isn't terribly accurate. Two homologous chromosomes contain the same loci (in healthy individuals), but may contain different alleles. --♦♦♦Vlmastra♦♦♦ (talk) 03:37, 24 January 2008 (UTC)

No need to ask your bryologist. I have a bryophyte library here and can cite numerous sources from varied leading authors calling these structures leaves without any weasel words. Consider this quote from Crum and Anderson's Mosses of Eastern North America (one of the leading moss Floras in print, v. I p.13, description of Fontinalaceae): "leaves in 3 rows and sometimes conspicuously 3-ranked". Or from Wilf Schofield's Introductory Bryology (p12, general description of moss structure): "The gametophyte consists of an axis, usually termed a stem, and this axis bears leaves." Or from Bryophyte Ecology, edited by A. J. E. Smith (p.114, chap. on Desert Bryophytes): "It is a very general feature of arid region perennial mosses that their leaves change position markedly between the dry and imbibed states." Or from the primary literature "Phenology and Reproductive Biology of Syntrichia inermis..." by Lloyd R. Stark in The Bryologist 100(1):13-27: "It is a distinctive species, recognized by the coiled leaves when dry." Or from authors of India, Biology of Bryophytes by R. N. Chopra and P. K. Kumra (p286 on external water conduction): "In many mosses leaves are closely placed on the stem." Or from New Zealnd authors Bill and Nancy Malcolm The Forest Carpet (p.56): "In most mosses the central region of the leaf thickens into a midrib." In short, you would actually be hard pressed to find any bryological literature that did not call these structures leaves.

There are large difference between the leaves of a waterlily and the leaves of an agave. There are large differences between the leaves of a pine and the leaves of a philodendron. There are large differences between the leaves of a fern and the leaves of a club moss. There are differences between the leaves of a liverwort and the leaves of a moss. An expanded section on general moss morphology and anatomy would certainly be appropriate (and is on my list of things to do), but emphasizing the differences between one taxon and one other taxon would not be appropriate. All modern cladistic studies agree that "leaves" evolved multiple times, even among the vascular plants. So, having vascular tissue in the structure is nothing special. The leaves of ferns evolved independently of the leaves of seed plants, and both evolved independantly of the leaves of lycophytes. Even though they all have "true" leaves in the sense meant by Raven, "true" means nothing. It's merely a human label and is redundant with the fact that those groups are vascular plants.

The definition of diploid is accurate enough to explain what diploid means when it appears as a parenthetical statement glossing the word "diploid" on a page about mosses. More precision may be found by following the link. Your revision introduced the word homologous, which is why I reverted it. Defining an unusual word like diploid by using another unusual word like homologous is not good practice. --EncycloPetey (talk) 04:02, 24 January 2008 (UTC)

Quotation problem?

I was researching mosses on the internet and came across a site with language identical to text in the "Cultivation" section and "Mossery" subsection of this page. It is unclear to me which site is borrowing from which; whichever way it is, the borrowing is not acknowledged, nor could I readily find source notes on either site that would clear up the uncertainty. The site in question is http://www.spiritus-temporis.com/moss/cultivation.html. --ValliNagy —Preceding undated comment was added at 17:08, 11 September 2008 (UTC).

That site is presenting Wikipedia content. You can see the notice at the bottom of the page, and I can find other sections of this same article quoted there which I am certain did not come from that site. --EncycloPetey (talk) 00:21, 13 September 2008 (UTC)

Growth rate

Does it say anything about growth rate of moss here? Didn't see it but came here looking for that specifically. Icemuon (talk) 01:17, 25 April 2009 (UTC)

"Moss" is a division-level taxon of about 12,000 different species. Looking for growth rate information on "moss" is like looking for growth rate information on "flowering plants". That sort of information isn't relevant to a high-level grouping where the information will be so highly variable. --EncycloPetey (talk) 06:07, 26 April 2009 (UTC)

Meiosis vs. mitosis

Can we add to the life cycle portion, which generation is reproduced through Meiosis vs. Mitosis? Elleacampbell (talk) 15:15, 25 June 2009 (UTC)

Both generations are produced by mitosis, since both start from a single cell that divides (by mitosis) to become multicellular. Only the spores are produced by meiosis (this is true for all land plants), and that information is already presented in the article under "Life cycle". --EncycloPetey (talk) 15:39, 25 June 2009 (UTC)

External link

I would like to add a link to the External Links section of this page.

I maintain a site which mostly consists of photographs of mosses.

The site url is: http://www.andrewspink.nl/mosses/ The site title is: Andrew's Moss Site (photos of mosses)

Andrew Spink Andrewspink (talk) 09:34, 25 September 2009 (UTC)

.We usually do not link to external sites unless they provide a significant source of information that is not likely to be included in the article. I've looked at your site ad many of your pictures are of liverworts. It is not just about mosses, but is about bryophytes (mosses and liverworts). It would not be appropriate to link from the Moss article. --EncycloPetey (talk) 13:32, 25 September 2009 (UTC).

Just for the record, it's likely that Andrewspink is using the English word "moss" incorrectly. In many (?most) Germanic languages, the cognate of "moss" is more generic than in modern English. For example in German "Moos" (plural "Moose") includes mosses, liverworts and hornworts which are "Laubmoose", "Lebermoose" and "Hornmoose" respectively. Noting that his website is in the Netherlands, I'm assuming the same is true of Dutch. In Modern English, "moss" does not include "liverwort". Thus Watson's classic text on British bryophytes is called "British Mosses and Liverworts"; it could not be called just "British Mosses". Peter coxhead (talk) 02:45, 28 March 2011 (UTC)

“rm blurry image; does not add to article”?  I disagree.

  I happened to see, today, what I thought was the most perfect example I had ever seen of a small moss growth, showing both the gametophyte and sporophyte forms.  With some difficulty, I took this photograph.  It was not easy, as this was too small to photograph directly with my camera, and too large to put under my microscope; beside which I would not have been able to put it under my microscope without severely damaging it in the process of removing it from where I found it.

  In spite of the crude and awkward method to which I had to resort to take this picture, I thought it came out beautifully.  A quick examination of this Wikipedia article on Moss, and a quick browse of the Wikimedia Commons failed to show any other image that comes anywhere close to showing what this does, as well as this does.  Though it could use a better caption than I was able to think of, I thought this picture would be a very worthwhile addition to this article, so I uploaded and added it.

  Apparently, someone disagrees with me about the value of this image.  Not an hour after I added it, my change was reverted, with the explanation “rm blurry image; does not add to article“.  Blurry?  I admit that the image is not perfect, but the word “blurry” implies a far greater lack of focus and sharpness than this image shows.  The background, of course, is completely blurred out, but in an image of this type, I think that is desirable anyway, as it prevents the background from distracting from the subject.  It is far sharper and in better focus than is needed to clearly show what it shows, which is the distinction between the gametophyte and sporophyte forms of this moss.  Surely, this distinction is an important thing to show in this article.  There is no other image in this article which shows this, and I cannot find another image anywhere on the Commons that shows it nearly as well.

  And not that I would argue for the removal of any of the other images that currently appear in this article, but there are several which surely contribute less to this article than mine would.

  —Bob Blaylock (talk) 03:10, 27 March 2011 (UTC)

I wasn't involved in the initial removal, but I'm afraid that I agree with it.

• I agree that the article does really need a good image showing a sporophyte growing from a gametophyte; the best in the article at present is the "red moss capsules" one, but it isn't sufficiently close-up to show the detail that would be useful.
• I agree that if it were sharp, your image would be a good addition; its content is just about perfect.
• However, and doubtless there are subjective preferences here, your image is just too out-of-focus for me. I have downloaded the original and spent some time trying to sharpen it with Photoshop, but it doesn't make much difference. The original simply not sharp enough (a.k.a. too blurred).

So I have removed the image again. Please accept that I'm simply trying to make a Wikipedia article as high quality as possible. Peter coxhead (talk) 02:21, 28 March 2011 (UTC)

Would this from commons be any better?  Velella  ^{Velella Talk}   15:30, 28 March 2011 (UTC)

No, the sporophytes aren't fully developed and are still enclosed within the calyptrae (i.e. gametophyte tissue). This Pogonatum image has better developed sporophytes, but they're still inside the gametophytic calyptra. I do find an Atrichum image that shows a clear sporophyte on an extended stalk. There might also be some good images in Category:Pottiaceae. I didn't look because my browser doesn't seem to want to load thumbnail images right now, but mosses in that famiy have characteristically short and erect gametophytes, and often have sporophytes present. --EncycloPetey (talk) 19:13, 28 March 2011 (UTC)

This image isn't bad: Barbula spadicea, but a sharp, natural-looking image of a single mature sporophyte attached to its gametophyte is what is really needed Peter coxhead (talk) 17:05, 10 April 2011 (UTC)

  I remembered, earlier today, just as I was in my final stages of getting ready to go to work (and thus not able to take time to do anything about this at that time) this picture that I produced nearly a year ago.  Technically, it's a good picture, but I really don't like it.  It looks too “unnatural” and the gametophyte is shriveled and not very prominent.  This one was made by putting the moss on a flatbed scanner, and scanning it.  It's nice and sharp, at least, but I really don't think it looks as good as my other picture, which I still disagree is too “blurry”. — Preceding unsigned comment added by Bob Blaylock (talk • contribs) 06:56, 29 March 2011 (UTC)

I can give this page a sharper picture showing how the sporophyte grows from the end of the gametophyte if anyone would like. Trainmastercrc (talk) 18:17, 29 December 2011 (UTC)

Looks like nice proposal :). If You think it's just better, be bold ! :). If You a bit doubt yourself, you may show us the image here on the talkpage first :) Reo ⁺ 22:25, 29 December 2011 (UTC)

Cool. When spring arrives and I can get some nice mosses from my backyard with their sporophytes on 'em, I'll do that. — Preceding unsigned comment added by Trainmastercrc (talk • contribs) 22:36, 10 January 2012 (UTC)

Mosses and water

There are some places in the article where the implication is that mosses generally (as opposed to some mosses or even most mosses) require moist habitats to live in; these statements are not clearly sourced. What can be sourced is that mosses are actually more tolerant of dehydration than almost all vascular plants: "vegetative DT [=desiccation tolerance] is rare, except among bryophytes. Evolution of this trait was important in facilitating the colonization of the land, but was lost subsequently in vascular plants." Stefan A. Rensing; et al. (2008), "The Physcomitrella Genome Reveals Evolutionary Insights into the Conquest of Land by Plants", Science, 319 (5859): 64–69, doi:10.1126/science.1150646 {{citation}}: Explicit use of et al. in: |author= (help) Here's one example from the article as at 01:29, 19 April 2011 which concerns me: "Since mosses have no vascular system to carry water through the plant, they must have a damp environment in which to live, and a surrounding of liquid water to reproduce." This seems to me to be misleading of mosses generally. Mosses like Tortula muralis (Wall Screw-moss) are commonly found on walls in full sun in the British Isles; there's nothing "damp" about this environment. Although mosses don't have the tissues which botanists call 'vascular', many do have water-conducting systems. Although there must be moisture for the very last stage of fertilization, this can be provided by rain, so that only a very temporary "surrounding of liquid water" is needed. Peter coxhead (talk) 21:39, 19 April 2011 (UTC)

Indeed, this is one of the most common misconceptions about mosses and about bryophytes in general. Most bryophytes only need free water for a short period, because they have a rapid life cycle, or because they dehydrate completely during the dry season, or because they live in rain forests (tropical or temperate) where there is daily precipitation. --EncycloPetey (talk) 22:12, 19 April 2011 (UTC)

I don't entirely agree that the text is misleading. That full sun wall in the British Isles is going to be pretty damp whenever it rains and for some time afterwards. It does rain quite often in most of the British Isles, as I understand. The text does say that mosses can survive months of dessication and can grow in sunny seasonally dry habitats (like your wall). I don't have a good technical source for this, but sounds like you do; please add it. I also do not have a good technical source for information on moss water conduction so I do not want to go into details about it in the text. I also thought a general audience might not care. Sounds like you do have a good source, though, and could easily add it. The more references and the more technical, the better! Dog Walking Girl (talk) 23:18, 24 April 2011 (UTC)

Tortula muralis is not limited to the British Isles. It also grows commonly across North America, including California and Nevada, where it doesn't rain for many months at a time. The plant still thrives even without water for much of the year. Hence, the information about mosses growing only in damp environments is very misleading; it's a common misconception and many people try to refit the facts to this preconception. But the preconception is incorrect. I expect to add fuller information about water and bryophytes, but don't have the time to invest in such a large undertaking right now, in part because of work and in part because I don't have easy access to a great library anymore. It will have to wait until I have some significant time off work. --EncycloPetey (talk) 23:39, 24 April 2011 (UTC)

Is the lead image wrong?

I honestly cant see anything in the picture that has to do with moss. If I'm wrong its fine, but..Im just not seeing it. Should we replace it without something more accurate? I just don't think it should have to be this hard to discern the meaning of a picture. 74.132.249.206 (talk) 13:30, 10 April 2012 (UTC)