Talk:Leaf

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To-do list for Leaf: edit · history · watch · refresh · Updated 2009-11-24 Here are some tasks awaiting attention: Expand : Lead section should be fleshed out Add section on evolutionary origin of leaf and early fossils Add section on multiple origins of leaves Add section on leaf-like structures that are not leaves Add section on leaf physiology Add section on abscission and deciduousness Verify : Add references Other : Article is rather 'listy' - try to include more prose. Priority 1 (top)

This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Peer reviewers: Eagle Pudding.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 02:20, 17 January 2022 (UTC)[reply]

This page has the potential for upgrading to GA. Both Danish and German versions are at GA standard (see main page). A couple of other well written pages which are worth looking at are French and Spanish. --Michael Goodyear (talk) 18:28, 25 February 2016 (UTC)[reply]

it seems like veins is a large enough subject for its own page? — Preceding unsigned comment added by Greg.collver (talk • contribs) 15:26, 9 November 2017 (UTC)[reply]

Near the start you said .."at the expense of water loss" Couldn't that be phrased better by saying "at the expense of water vapour" (or simply water) I dunno but the double negative frazzled me a bit

For extra credit, name the type of leaf in the picture.  :-) --LMS

Maple, but I'm not sure what species. Vicki Rosenzweig

Leaf me alone! Let's add a section on bad puns and idioms involving relating to the word leafInvertRect 00:50, 4 September 2006 (UTC)[reply]

OK, what kind of maple leaf, then? (I don't know if one would be able to tell just by looking at the leaf.) --Larry Sanger

Green and yellow. Probably the one Cummings wrote about. :o) --KQ

The "replacement leaf was not an improvement (too dark). Also, the photo has a useful caption that was apparently not read by the person that changed the photograph as it made no sense with the darker image - Marshman 18:33, 25 Mar 2004 (UTC)

Why show just a piece of a leaf? A whole leaf would be better, unless it zooms in to show the micro structure. The cut leaf seems rather sad - too reductionist... Khaydock (talk) 08:52, 13 May 2013 (UTC)[reply]

I have added something about humidity air boundry layers to "adaptations". In general, the Adaptations category is overloaded, but I'm not sure where else it should go.

Are you sure about the rustling of leaves as an adaptation to reduce the boundary layer? i had always thought it was an adaptation to prevent damage to the leaves in wind. David D. (Talk) 17:31, 20 October 2005 (UTC)[reply]

• File:SEM leaf (1300x).jpg
• File:SEM leaf (350x).jpg
• File:SEM leaf (2900x).jpg
• File:SEM leaf (1875x).jpg

It would help to identify what is shown. The idea of looking at "interesting junk" sort of eliminates usefulness for the encyclopedia - Marshman 04:50, 26 January 2006 (UTC)[reply]

Well, two of them show a stoma...

Nevermind. They're already over there. :-) — Omegatron 06:11, 26 January 2006 (UTC)[reply]

Remember that the would stoma (pl. stomata means the opening in the plant epidermis. The opening with its surrounding cells is properly termed a stomatal complex (among other names), although stoma or stomata is often applied to the complete structure in the lietrature now. --EncycloPetey 20:34, 27 January 2006 (UTC)[reply]

Twice in this document i have found an equals sign following an open bracket, is the equals sign really needed? wouldn't "(Middle Leaf)" be sufficient? Murdochious 09:30, 7 June 2006 (UTC)[reply]

see above

You'll need to be more explicit. David D. (Talk) 19:50, 11 October 2006 (UTC)[reply]

The following webpages present text information and microscopic images on leaf anatomy, in particular on the adaptation of leaves to various environmental conditions. Do you think this contribution to be worthwile to be linked?

[1]www.vcbio.science.ru.nl/en/virtuallessons/leaf/

less than 2 days off semi-protect, and 3 RVs already. Let's keep our eyes peeled for more unconstructive edits! Debivort 19:20, 21 November 2006 (UTC)[reply]

"1 An epiderpenis that covers the upper and lower surfaces" Uh, I don't know much about leaves, but... Shouldn't this be epidermis or something rather than... epider-penis...? o_o

Guess that'd be one of those "unconstructive edits" I just read about. —The preceding unsigned comment was added by 216.14.157.144 (talk) 09:35, 14 March 2007 (UTC).[reply]

That's exactly right. You are welcome to fix the article next time you spot any trickery like this too... Debivort 17:18, 14 March 2007 (UTC)[reply]

A "history" section of leaves should be added

Leaves have evolved independently at least three times. I beleieve the earliest leaves known as fossils are microphylls of Baragwanathia from the Upper Silurian, but this is not a precursor of what most people think of as leaves, since Baragwanathia was a Drepanophycalean lycophyte. --EncycloPetey 23:30, 18 April 2007 (UTC)[reply]

The article starts with explaining that leaves are above ground parts. Is that the best, and only way to describe it, considering the various places and directions that plants can grow? Or is that the most practical way to say it, allowing people to form their own conclusions about the few exceptions? M. D. Vaden of OregonMdvaden 05:05, 24 July 2007 (UTC)[reply]

This is a problem. There are modified leaves that occur underground. Perhaps the word "typically" should be appended or maybe the above ground phrase should just be removed.Michaplot (talk) 22:42, 30 September 2009 (UTC)[reply]

An image of a water lilly would be a nice addition, as it's so unique. I'd normally add it myself but the article is pretty full as is, so it might require removing one or rearranging things a little. There should also be some mention of heterophylly (where plants have more than one type of leaf). Richard001 07:17, 8 September 2007 (UTC)[reply]

I've got a tropical like plant that I noticed appeares to be "sweating" with drops of water appearing on its leaves. Is this normal or a function of over-watering?Tom Cod 16:24, 20 October 2007 (UTC)[reply]

Without knowing more about the specifics of where your plant is located, what kind of plant it is, and the environment, it would be difficult to say. But in general, yes. One of the functions of leaves is to lose water by transpiration, thereby helping to pull mater and dissulved nutrients up from the roots. --EncycloPetey 16:27, 20 October 2007 (UTC)[reply]

It's normal. During the day the water in a plant is under tension due to transpiration from the leaf. At night when there is no transpiration, but water is still entering through the root, a positive pressure can be reached by morning. This result in the extrusion of xylem fluid from specialsed leaf cells called hydathodes. The phenomenon is know as guttation. David D. (Talk) 02:43, 2 November 2007 (UTC)[reply]

WHY IS THIS PAGE PROTECTED? IM GANNA FIND OUT WHO DID THIS —Preceding unsigned comment added by 68.127.90.49 (talk) 22:21, 16 February 2008 (UTC)[reply]

The page is temporarily protected (again) because the vast majority of edits made here by unregistred users have been vandalism or other non-constructive edits. See Wikipedia:Rough guide to semi-protection. --EncycloPetey (talk) 22:32, 16 February 2008 (UTC)[reply]

Perhaps it's just me, but it seems as if there are too many pictures in this article in comparison to it's length. For example, there are three pictures of fall leaves, while one would suffice. --71.225.75.183 (talk) 18:51, 25 May 2008 (UTC)[reply]

A user states "The fact that an arrangement of anything in nature can be described by a mathematical formula is not in itself mysterious"; no reference or other information to support this statment is given, and is an opinion/philosophical statement more than a scientific fact; moreover, many do believe that finding such precise mathematical patterns in nature have their oringins outside of the physical realm (i.e. God), and would be statistically impossible if left to mere evolutionary chance. --Tarquilu (talk) 15:40, 27 June 2008 (UTC)[reply]

The statement in the article you have quoted is not a reference to evolution; it is a statement regarding predictable geometry and cell patterning from an apical meristem. This same mathematical pattern appears in the number of rabbits in a population that starts with one male and one female, and is simply a consequence of the process of breeding. This pattern was discovered by Fibonacci, and it is the same pattern that appears in leaf numbers on the stem, because it originates from the number of cell divisions that have occurred, a process not unlike the growth of the rabbit population. The appearance of a regular and predictable pattern in science is never mysterious; it is the underpinning of science to assume that such predictability exists in nature, to describe it, and to provide a testable hypothesis regarding the underlying causes. Your viewpoint, as stated, rejects the entire idea of science altogether, which cannot reasonably be considered NPOV in an article on a scientific subject. --EncycloPetey (talk) 16:29, 27 June 2008 (UTC)[reply]

And why does 'science' assume that predictability exists in nature? Predictability comes out of knowing that something (e.g. a pattern) exists and can be reproduced or found. My understanding of nature does not reject idea of science if it is true that an all wise God created reality as we know it, with all its predictable patterns and mathematics and engineering and intelligence, and if he gave us a limited intelligence to describe it, and to provide testable hypothesis regarding His creation. Why does 'science' assume that predictability exists in nature? Is it because humans, like Fibonacci, you and I, and most others have always seen patterns in nature, such as platonic solids in carbon, viruses, and protoza? Or is there a more scientific explanation why science assumes that predictability exists in nature? The viewpoint that I hold was also held by many notable scientists (e.g. Michael Faraday, Louis Pasteur); now did their viewpoint hinder them from applying the scientific method and contributing to our understanding of nature? And why is your viewpoint a NPOV? Is it because science assumes it is? Why does 'science' assume that predictability exists in nature? Is it because predictability is found in all branches of study, and will continue to be found. The fact that predictability exists does not preclude the possibility that these patterns are there because a creator put them there so that they could be described and tested to allow us to obtain a glimpse of his infinite wisdom. If this is the case, then this phenomenon is not only mysterious, but also illustrious and wonderful. The parallel example seen in population growth is a consequence of the process of breeding, but it is anything but simple; breeding and the bringing forth of life are miracles in themselves that we can only observe and describe, but could never cause to happen like God describes in Genesis chapters 1 & 7 of the Bible where he spoke and everything came into being. Please substantiate or eliminate the objectionable statement, or provide a statement that gives equal credence to other's viewpoint on this subject.--Tarquilu (talk) 16:36, 28 June 2008 (UTC)[reply]

Hi Tarquilu. Your additions raise several problems. The first is that creationism is not a scientific viewpoint, and as such doesn't really belong in a scientific article. In some cases it might be different, but in one mention in an ICR publication really doesn't warrant mention here.

While our "neutral point of view" policy requires that we document all notable opinions on a topic, it needs to be done in a manner that does not create undue weight. I think it's safe to say that all scientific studies on leaf arrangement have not given credence to the idea that "divine intervention" could be responsible for leaf arrangement. Your source is not a scientific publication. It also isn't a well-known "popular" article or topic. If leaf arrangement was a topic that was widely used by creationists as evidence for the existence of God, it might be worth mentioning. But to place it on equal footing with real explanations gives undue weight to a fringe idea.

As an aside, it's also inappropriate to describe this as "evidence of intelligent design". Willson does not call it that. When it comes down to it, associating ICR-style creationism with ID is unfair to creationism. At least they propose hypotheses, even though they are palpably incorrect. Guettarda (talk) 04:51, 29 June 2008 (UTC)[reply]

And by the way - you're right that the current wording is far from ideal. But making it worse isn't a solution. Guettarda (talk) 04:56, 29 June 2008 (UTC)[reply]

I'd suggest deleting that paragraph. I don't think it adds anything to the article, even if the English usage is fixed.

I also wonder why Tarquilu finds the first sentence objectionable; from his own words we can tell that he doesn't find that mathematical rules can be fitted to observations mysterious. A new-ager might want to present this as a mystery, but I can't see why a creationist would. Lavateraguy (talk) 09:10, 29 June 2008 (UTC)[reply]

In stating that the phenomenon is not mysterious, the author attempts to take away from the wonderment that such a pattern exists, which is the very reason why I believe God placed such patterns in nature (i.e. Romans 1:18-20, Psalm 19:1-4), specially such a prevalent one. I hope not to emphasize that it IS mysterious, because the word does not really discribe the phenomenon. I don't think the pattern of arrangement on leaves is mysterious; it is meaningful and points to something greater than ourselves. Anyway, what does the author of the statement mean that it is not mysterious? Your right it does not add to the anything to the article, but takes away from it. Let every reader on an individual basis decide what such an observable pattern means to them, not being influence one way or another; but if they are influenced one way, they should also be able to read other viewpoints.--Tarquilu (talk) 14:29, 29 June 2008 (UTC)[reply]

I've deleted the paragraph. I don't think it adds to the article. To me, it's self-evident that it's not mysterious. I won't be offended if someone reverts, but please make it more relevant.--Curtis Clark (talk) 18:05, 29 June 2008 (UTC)[reply]

I'm looking for information on leaves that have defensive mechanisms such as briar patches and/or poison. Any idea where I should look? Pvegeta (talk) 18:14, 17 October 2008 (UTC) --look in the Nettle family Urticaceae or the poison ivy family Ancardinaceae. --Eagle Pudding (talk) 02:03, 27 June 2016 (UTC)[reply]

Ideally, the leaf anatomy section would rely heavily on the books by Katherine Esau, Abraham Fahn, and Paula Rudall. I do not know when or if i will find time to rewrite parts of this article. 128.171.106.250 (talk) 02:58, 15 July 2009 (UTC)[reply]

 The Leaf morphology section takes up a quarter of this page and it only has 1 citation from 1977 about palm leaves. I will try to find some other sources but if anybody else can help it would be much appreciated. Eagle Pudding (talk) 02:15, 27 June 2016 (UTC)[reply]

I almost reverted this myself, but the leaves are almost certainly not tulip leaves, and are very likely to be iris. The easiest solution might be to remove the photo.--Curtis Clark (talk) 14:47, 19 July 2009 (UTC)[reply]

Since Foliage redirects here, it should be defined somewhere in the article.. 24.85.243.172 (talk) 17:03, 3 June 2010 (UTC)[reply]

Under "Anatomy": (Quote)A structurally complete leaf of an angiosperm consists of a petiole (leaf stem), a lamina (leaf blade), and stipules (small processes located to either side of the base of the petiole). The petiole attaches to the stem at a point called the "leaf axil."(End quote) This is very confusing for a non-botanist since the first sentence implies that the petiole is the stem. Can someone please make this passage clear? Axel 01:25, 22 August 2010 (UTC)

The petiole is a stem, which connects to other stems like branches or the main stem, do you have any suggestions on how this might more clearly be presented? Hardyplants (talk) 01:28, 22 August 2010 (UTC)[reply]

The petiole is not a stem—it is anatomically part of the leaf. A better word is "stalk", which is descriptive but has no formal botanical definition to misuse.--Curtis Clark (talk) 04:31, 22 August 2010 (UTC)[reply]

Thank you for the correction, I was using stem with a generic meaning which was incorrect and confusing. Stalk is a good choice, because the petiole is morphologically an extension of the leaf and not of the stem. Hardyplants (talk) 05:08, 22 August 2010 (UTC)[reply]

"trees shed their leaves which would otherwise damaged by freezing temperatures".. in the introduction there needs to be a "be" between "otherwise" and "damaged". i cant edit the article because it's locked; anecdotal evidence that wikipedia would be better with a more open format. — Preceding unsigned comment added by 174.109.99.78 (talk) 05:33, 21 June 2011 (UTC)[reply]

Done. (Please see message on your talk page.) Regards, Richard New Forest (talk) 12:08, 21 June 2011 (UTC)[reply]

In the section titled Major Leaf Tissues the images labelled Palisade Mesophyll and Spongy Mesophyll seem to have been crossed up. — Preceding unsigned comment added by Brothernight (talk • contribs) 20:27, 27 February 2012 (UTC)[reply]

No, I think that is correct, but the palisade mesophyll image is an unusual view. It is a view that comes from focusing down, say from the top of the leaf, through the cells to about their middles. It is a cross-section of each cell. As you point out, it is confusing enough that I'm going to remove it from the page; there are plenty of other illustrations. Nadiatalent (talk) 22:51, 27 February 2012 (UTC)[reply]

Nadia or Petey or whoever is in a position to react. I am by now autoconfirmed and wish to add an item. The article does not permit. Procedure? Thanks. JonRichfield (talk) 11:56, 3 March 2012 (UTC)[reply]

Coding problem, I think. Fixed. Nadiatalent (talk) 13:50, 3 March 2012 (UTC)[reply]

In the section on Morphology, the subsection on Arrangement on the stem, the article says:

There is a regularity in these angles and they follow the numbers in a Fibonacci sequence: 1/2, 2/3, 3/5, 5/8, 8/13, 13/21, 21/34, 34/55, 55/89.

The details in the sequence here are contradicted both a few sentences down in the examples provided, and in the article Phylotaxis.

The Fibonacci series runs

1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89 ...

Each new number is the sum of the two before it. The example provided in the quote makes fractions of each Fibonacci number and the one following it. In fact, it should be the Fibonacci number and the SECOND one following it, i.e.

1/2 (because there are two 1's), 1/3, 2/5, 3/8, 5/13, 8/21, 13/34, 21/55, 34/59 ...

I'm a little reluctant to make the correction. I might go ahead if someone else doesn't after a while. Uporządnicki (talk) 13:18, 11 May 2012 (UTC)[reply]

A new discovery. Could someone who knows more incorporate this? Malick78 (talk) 09:17, 1 July 2012 (UTC)[reply]

This information would belong in the carnivorous plant article, not in the general article about leaves. --EncycloPetey (talk) 21:19, 2 July 2012 (UTC)[reply]

Hello! This is a note to let the editors of this article know that File:Leaf Tissue Structure.svg will be appearing as picture of the day on December 3, 2012. You can view and edit the POTD blurb at Template:POTD/2012-12-03. If this article needs any attention or maintenance, it would be preferable if that could be done before its appearance on the Main Page so Wikipedia doesn't look bad. :) Thanks! —howcheng {chat} 12:19, 2 December 2012 (UTC)[reply]

Picture of the day

The fine scale structure of a leaf featuring the major tissues; the upper and lower epithelia (and associated cuticles), the palisade and spongy mesophyll and the guard cells of the stoma. Vascular tissue (veins) is not shown. Key plant cell organelles (the cell wall, nucleus, chloroplasts, vacuole and cytoplasm) are also shown.Image: Richard Wheeler

Archive – More featured pictures...

Leaf <----- (Redirected from Leaves). But no comment saying that → The Leaves is a band with an article in this wiki. --Schwab7000 (talk) 15:48, 13 February 2013 (UTC)[reply]

There's a link to leaf (disambiguation) at the top of the page, which has a link to the band. Guettarda (talk) 16:08, 13 February 2013 (UTC)[reply]

The article for leaf is very long (for good reason of course) and contains a lot of material that overlaps this article; confusingly so. One option would be to merge the two, but because of the size of the Leaf article, I recommend that the leaf shape sections of Leaf be incorporated into this article. I could do that myself, but would prefer first to hear from other editors who might have rival thoughts or projects. I am repeating this note in the talk page of the other article. JonRichfield (talk) 08:32, 1 June 2013 (UTC)[reply]

In the article it says the change of colour is caused by the response to the reduced sunlight and colder temperatures? However I've read many times that its actually cold temperatures and abundant sunlight that produces the strongest seasonal foliage. Ashton 29 (talk) 01:44, 22 May 2014 (UTC)[reply]

  The lack of enough sunlight causes a reduction in chlorophyll production which allow the pigments that are already there to not be masked by the green chlorophyll.  This unmasking is what give the leaves their color. Eagle Pudding (talk) 02:10, 27 June 2016 (UTC)[reply]

Hello! This is a note to let the editors of this article know that File:Leaf morphology.svg will be appearing as picture of the day on December 22, 2014. You can view and edit the POTD blurb at Template:POTD/2014-12-22. If this article needs any attention or maintenance, it would be preferable if that could be done before its appearance on the Main Page. Thanks! — Crisco 1492 (talk) 00:21, 30 November 2014 (UTC)[reply]

Picture of the day

A diagram showing different characteristics of leaves which are visible to the naked eye or under slight magnification. These can be used for identifying the species on which the leaves are found. This chart shows three aspects of leaves that can be differentiated: the shape and arrangement of the leaf, its edge (or margin), and the pattern of its veins.Diagram: Debivort and McSush

Archive – More featured pictures...

can you add an image of a leaf with spores? Valehd (talk) 02:39, 18 February 2015 (UTC)[reply]

Many other articles in botany have sections dedicated to its relation to humans: see for example the flower article or the tree article. It seems therefore that at least a segment of the community finds it agreeable. 92.13.134.77 (talk) 13:41, 5 September 2016 (UTC)[reply]

I agree that there could be a section on the relationship between leaves and people, but what was added is so unbalanced as to be misleading. Leaves as food, leaves as construction material, etc. are much more important. There's no point in duplicating Plant#Importance, but this could serve as a departure point. Peter coxhead (talk) 15:38, 5 September 2016 (UTC)[reply]

I tagged the article as needing cleanup. It's worded in a very technical way, and it does not contain clear definitions for terms that redirect to it. For instance, Midrib used to redirect here, but since there is no definition of the term in the article, I redirected it to Glossary of botanical terms § midrib. I may do the rewriting myself at some point, we'll see. — Eru·tuon 23:32, 7 September 2016 (UTC)[reply]

There is actually a sentence completely in French in the venation section. Seriously? Anyone know how to accurately translate it?

24.68.94.146 (talk) 21:00, 23 October 2016 (UTC)[reply]

Happened in June 2016. "Nervure tertiaire reliant les nervures secondaires."

24.68.94.146 (talk) 21:09, 23 October 2016 (UTC)[reply]

The article states "Leaves are the most important organs of a plant". That is an inaccurate statement coming from a leaf-centred POV, rather like saying feet are the most important organs of an animal. Some plants have never had leaves (e.g. liverworts) and others which evolved from ancestors with leaves have lost them again (e.g. Equisetum, Ephedra, cacti and many more). Plantsurfer 11:12, 11 March 2017 (UTC)[reply]

The article currently reads, "Some window plants such as Fenestraria species and some Haworthia species such as Haworthia tesselata and Haworthia truncata are examples of xerophytes.[12] and Bulbine mesembryanthemoides.[13]" I clicked through to the Bulbine article, but it isn't clear whether it would be a "window plant." Anyone know what was intended here? IAmNitpicking (talk) 19:35, 26 February 2020 (UTC)[reply]

It is a window plant. Try Googling it. Plantsurfer 19:40, 26 February 2020 (UTC)[reply]

I've never encountered the phrase "window plant" before today. In any case, you're saying that the errant phrase belongs before the "are"? IAmNitpicking (talk) 20:22, 26 February 2020 (UTC)[reply]

Do editors think the repeated disruptive edits by Sanarth Patil rise to the level of a ban request? IAmNitpicking (talk) 15:49, 30 June 2021 (UTC)[reply]

Some about plants leaves 106.210.41.110 (talk) 11:48, 12 April 2022 (UTC)[reply]

Leaves are specialized photosynthetic parts of a plant, but they are not (as the current short description implies) the only such parts. Note that many plants (e. g. most cacti, asparagus) have no or very reduced photosynthetic leaves and conduct all their photosynthesis in stems. I probably should "Be bold" and just change it, but I've never touched the short description and thought it wouldn't hurt to ask. IAmNitpicking (talk) 02:31, 18 January 2023 (UTC)[reply]

Lately I've been looking at the three pages Leaflet (botany), Compound leaf (which redirects to Leaf#Divisions_of_the_blade), and Leaf with a view to provide more detailed info about compound leaves. In my view neither the "Leaflet" nor the "Leaf" page provide a good explanation of compound leaves. I am proposing to remove the redirect and create an actual article at "Compound leaf" (which will cover the concept of "leaflet"), and redirect "Leaflet (Botany)" to it. I welcome any input that others may have about this idea. This message appears on the other two pages as well.  Junglenut |Talk  11:35, 8 February 2023 (UTC)[reply]

The image labelled "Diagram of a simple leaf" has a caption listing the parts of the leaf, corresponding to the circled numbers affixed to parts of the leaf pictured in the diagram. There are 8 numbered parts, in the list, including #6, Petiole, but the diagram has no #6. It should be to the right of the #7 and twig stem, with an arrow and a bracket pointing to indicate the leaf stalk. Can someone fix this? 2001:56A:F0E9:9B00:E9A8:38DA:A0F1:691A (talk) 13:03, 10 September 2024 (UTC)JustSomeWikiReader[reply]