Talk:Pseudanthium

Merge with Head(botany) discussion

The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section. A summary of the conclusions reached follows.

The result of this discussion was boldly merged D O N D E groovily Talk to me 13:12, 24 February 2012 (UTC)

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A merge banner was posted on the Head (botany) article. I don't have an opinion as to whether they should be merged or not. There seems to be a variety of terms that mean roughly the same thing, but do they mean exactly the same thing? If so, it seems like the articles should be merged.

• Head (botany) - The Head (botany) article implies, somewhat ambiguously, that head and capitulum are the same thing. The Head (botany) does not link to this article.
• Flower head - This term redirects to the Head(botany) article right now. This article states that it is exactly equivalent to pseudanthium.
• Pseudanthium - Applies to flower structures from numerous families according to this article.
• Capitulum - This article implies that this term applies only flowers of Asteraceae. I couldn't verify that this was true.
• Calathid - This article implies that this term applies only flowers of Asteraceae. I couldn't verify that this was true. This seems to be a rarely used term. The term is not defined in the Wikipedia Glossary of botanical terms article.
  

Another issue in all this is whether any of these terms would be appropriate to describe an Asteracea family flower structure that does not have differentiated flowers. For example, the flowers of the rubber rabbitbrush Ericameria nauseosa.--Davefoc (talk) 20:53, 6 May 2011 (UTC)

The term, discoid, is used to describe flower heads that only have disk flowers like those of rubber rabbitbrush.--Davefoc (talk) 14:02, 10 May 2011 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

calathid, calathids, calathidia, calthidium, calathide?

The article contains this sentence: "Pseudanthia are characteristic of the sunflower family (Asteraceae), where they are called calathidia, calathids or capitula."

The various forms of calathid are very rarely used terms. The following on-line botanical glossaries do not mention any form of the word:
http://ucjeps.berkeley.edu/interchange/JM_glossary.html
http://glossary.gardenweb.com/glossary/
http://botanydictionary.org/
http://davesgarden.com/guides/botanary/go/1127/

In addition, the book, Plant Identification Terminology (2001), by James G. Harris and Melinda Woof Harris does not have a definition for the term.

A google scholar search for calathid returned very few papers that used the term in a botanical sense. The most significant results (both papers might require registration):
http://www.springerlink.com/content/n0r4w6l641l38383/fulltext.pdf - A 1944 paper discussing the formal description of flowers. According to the paper various forms of the terms have been around for awhile. The paper reports that calathide was introduced in 1815, however it does not specifically refer to calathid as being a valid term.

www.academicjournals.org/jmpr/PDF/pdf2012/30Jan/Bibalani%20and%20Taheri.pdf - Investigation on flowering period of Asteraceae members in the Shanjan region Shabestar district, Northwest Iran (usage for honeybees) - This paper contains the same sentence that appears in the Asteraceae Wikipedia article: "The most evident characteristic of Asteraceae is perhaps their inflorescence: a specialised capitulum, technically called a calathid or calathidium, but generally referred to as flower head or, alternatively, simply capitulum."

The source of this sentence according to the Wikipedia Asteraceae article is the 1966 book, "A dictionary of botany, including terms used in bio-chemistry, soil science, and statistics".

In summary there are not any recent botanical glossaries that define the term and there are almost no links in Google Scholar for any use of the term while Google Scholar links to numerous papers that use capitulum, flower head and Pseudanthia. Based on the above it is my intention to delete the terms calathid, calathids and calathidia from the article unless there is discussion to the contrary.--Davefoc (talk) 08:06, 26 February 2012 (UTC)

Move proposal

The article starts by giving "capitulum" as a synonym of "pseudanthium". Now it's true that capitulum has multiple meanings, so using "Pseudanthium" as the title avoids the need to disambiguate, but searching for capitulum Asteraceae in Google Scholar gives me 13,600 hits as opposed to 221 for pseudanthium Asteraceae. Hence I'm inclined to move the article to "Capitulum (flower)". Comments please. Peter coxhead (talk) 10:54, 14 February 2021 (UTC)

Are we sure that capitulum is synonymous with pseudanthium , or is capitulum one of a few different types of pseudanthium? Hardyplants (talk) 11:22, 14 February 2021 (UTC)

@Hardyplants: I've learnt from experience not to be sure of anything in botanical terminology. Different sources (often apparently representing different schools or traditions) use terms as though they were unambiguous, but it turns out that they use them differently. My prime concern is to get an article that covers the Asteraceae and allied families. Beentje (2010), The Kew Plant Glossary, uses "capitulum" for "a compact cluster of ± sessile flowers" (p. 25). Stace (2019), New Flora of the British Isles, uses the term for Asteraceae and Dipsacaceae (p. 1124). As far as I can tell this is a clear and sourceable usage which can be turned into an article.

"Pseudanthium" seems to be a much vaguer term as shown by the long, and mostly unsourced, list of families the article says have them. Beentje says a pseudanthium is "an inflorescence consisting of several reduced flowers, the whole resembling a single flower", giving Euphorbiaceae and Cornus as examples (p. 94). This doesn't make a coherent topic for an article; there's no botanical or evolutionary relationship between the inflorescences of Euphorbiaceae and Cornus. "Pseudanthium" is just a glossary entry.

So, perhaps my proposal should be more clearly defined: Move the existing article to the title "Capitulum (flower)"; expand to cover the inflorescences of Asteraceae and allies (there's material in the Asteraceae article, which is how this proposal started); remove the unsourced list of families said to have pseudanthia.

See also entries for the two terms in Glossary of botanical terms, which might then need to be revised a bit. Peter coxhead (talk) 17:32, 14 February 2021 (UTC)

Harris & Harris define Capitulum as "a small flower head" and Pseudanthium as "a compact inflorescence of many small flowers that simulates a single flower." @Peter coxhead:'s data seems relevant to support a move. If there is a move, should the article name be "Capitulum (botany)"? That would be consistent with other botanical terms that could also be non-botanical terms. —Eewilson (talk) 19:47, 14 February 2021 (UTC)

I remove my suggestion about "Capitulum (botany)" as I see it can also refer to mosses. —Eewilson (talk) 21:06, 14 February 2021 (UTC)

I think that we want a page on the wider concept of a pseudanthium. This seems to be that page, other than the equation of pseudanthium with flower head and capitulum; I wouldn't see those terms extending to, for example, cyathia. And on the other hand, Campanula glomerata is described as having capitula, but I wouldn't consider those pseudanthia.

To add to the mix this paper uses the term capitule. Lavateraguy (talk) 22:36, 14 February 2021 (UTC)

Oppose: WRT comments and the article as it is now and what it could (and likely should) become, I can see how a merge would not be a good idea, and that pseudanthium is the broader concept and should remain such. —Eewilson (talk) 01:54, 16 February 2021 (UTC)

@Lavateraguy and Eewilson: the question I return to is whether "pseudanthium" is a concept and hence topic suitable for an article. The term does seem to be used differently, but generally simply means a group of flowers that in some way resemble a single flower, in a wide variety of different ways and with different evolutionary histories.

Anyway, what we need, I think, is a clear article on the capitula of Asteraceae and allied families, which have a common evolutionary history. My preference, as noted above, is to make this the article, and reduce "pseudanthium" to a glossary entry, but two articles could be another approach. Peter coxhead (talk) 09:53, 16 February 2021 (UTC)

@Peter coxhead: Well, I can't say I have the answer either way. I struck out my Oppose and offer this. If in a genus or species article of the Asteraceae family we need to link to a page for flower head, floral head, or a more "botanical" term synonymous for those (whatever term of these or another that the editor chooses to use, capitulum if that is the term), then my view is we need that article, which is as you say, Peter, what got this discussion started. If that article is to be Capitulum (flower), great. What I don't know and still don't understand is if pseudanthium is a broader concept in need of an article or can be reduced to a glossary term as you suggest. Selfishly, I say that as long as the need for a thorough explanation of the inner workings of an Asteraceae flower head is met, then I think we are on the right track. What I don't like, and would like to avoid, is to send people to the subsection in the Asteraceae article for an explanation of this concept. Actual question from a non-botanist: Are the terms capitulum and flower head synonyms? —Eewilson (talk) 18:11, 16 February 2021 (UTC)

@Eewilson: well, I'm not a (professional) botanist either. What I've learnt, as noted above, is that definitions of many botanical terms are slippery! Google offers me "flower head = a compact mass of flowers at the top of a stem, especially a capitulum" (from Oxford online dictionary).

The most detailed definition of "capitulum" that I can find is here, where "capitulum" has "head" as a synonym. (This source began as the Glossary for the Flora of North America. It doesn't contain "pseudanthium".)

I think that the following applies (where ">" means "includes")

"pseudanthium" > "flower head" > "capitulum" > "capitulum of Asteraceae"

Quite where this leaves us, I'm unsure! Peter coxhead (talk) 08:09, 17 February 2021 (UTC)

I think that the usages of the terms are non-hierarchical overlapping - you need a Venn diagram rather than a strict inclusion based ordering. The confusion arises because asteraceous flowers are good exemplars of all of pseudanthia, capitula, and flower heads. But if you consider other families there are pseudanthia which are not flower heads or capitula (e.g. cyathia, but also umbellate and corymbose pseudanthia such as in Apiaceae and Hydrangea), flower heads which are not pseudanthia or capitula (Echinops flower heads are composed of uniflowered capitula, though I could imagine someone calling this a compound capitulum, or including it among the pseudanthia), and capitula which are not pseudanthia (e.g. Campanula glomerata).

I presume that term calathid was invented for composite flower heads because they are simultaneously pseudanthia and capitula. Lavateraguy (talk) 10:12, 17 February 2021 (UTC)

@Lavateraguy: the problem is, as noted before, the inconsistency of definitions in different sources. Thus the terminal inflorescence of Campanula glomerata can be described as a "clustered head" (e.g. by Stace), and if "capitulum" is just the Latin equivalent of "head", then the species has a capitulum. But if you use this definition, which is much tighter, C. glomerata doesn't have a capitulum. Peter coxhead (talk) 19:44, 18 February 2021 (UTC)

Is there is a reason for not covering the inflorescence of composites at Asteraceae#Inflorescence (I suggest replacing the current heads with Inflorescence and Flower) and linking there, rather than having a separate article? If there is my best suggestion for the article title would be inflorescences of Asteraceae, as calathid (make that a redirect) is too obscure a term. Lavateraguy (talk) 19:22, 18 February 2021 (UTC)

@Lavateraguy and Eewilson: contrary to my initial view, I now think this is the best approach. The varying definitions and usages of the term "capitulum" make it essential to describe a particular type of capitulum strictly in context. So I suggest:

1. Construct a section at Asteraceae#Inflorescence.
2. If this turns out to unbalance the article, split it, creating an article at something like "Asteraceae inflorescence".

The Pseudanthium article can then be just a kind of list article, setting out all the different kinds of inflorescence that can be shown to have been called "pseudanthia". Peter coxhead (talk) 19:44, 18 February 2021 (UTC)

@Peter coxhead and Lavateraguy: Seems like a good approach. The Asteraceae article has Flowers->Floral heads and Flowers->Floral structures, and the whole Flowers section is hard to follow and seems disorganized. I think changing Flowers to Inflorescence (or Inflorescences - do you want singular or plural? I think singular.) in that article with appropriate subtopics can be part of the reorganization that I'm working on (unless someone else wants to jump in, then go for it of course). If it gets to be too much and should be moved out into another article, then we could address that, perhaps creating a redirect now (Inflorescence of Asteraceae? Inflorescences of Asteraceae? Asteraceae Inflorescence? etc. Got a preference? All of the above?). This does bring me back to a concern I have that in any lower taxon article, the need to link to "flower head" still will be addressed by taking you into a subtopic of Asteraceae, but as long as the prose and content are clear, that shouldn't be a problem. (Incidentally, that concern isn't what got this topic started, it was what I see as possible CLOP in the Floral heads subtopic in Asteraceae.) —Eewilson (talk) 20:12, 18 February 2021 (UTC)

The pseudanthium article seems to need a fair bit of work done on it, but unfortunately it's one of those cases where identifying the problems is easier than identifying the solutions. And I worry about overstepping the lines on WP:OR and WP:SYN.

Lets try - "A pseudanthium is an inflorescence which to some degree acts functionally as a single flower, e.g. the bracts or outer flowers of an inflorescence performing the pollinator attracting function of the corolla of a normal flower, or staminate and pistillate flowers of an inflorescence substituting for the stamens and carpels of a perfect flower. There is variation in the degree of specialisation and integration of the component flowers, and there is not a precise definition of the line between a pseudanthium and a non-pseudanthial inflorescence on the one hand, and between a pseudanthium and a flower homologous to an inflorescence (rather than the plesiomorphic angiosperm flower) on the other hand."

"The best know pseudanthium is the pseudanthial capitulum of Asteraceae, sometimes called a calathid, but pseudanthia occur in many angiosperm families, and are derived from several different inflorescence types; in Araceae from a spike, in Tordylium from an umbel, in Hydrangea from a corymb, etc." (I think a cyathium is derived from a cyme, but that one needs a citation.) 21:19, 18 February 2021 (UTC)Lavateraguy (talk) 21:21, 18 February 2021 (UTC)

You mean for the lead in the Pseudanthium article? —Eewilson (talk) 00:00, 19 February 2021 (UTC)

Yes? Lavateraguy (talk) 12:18, 19 February 2021 (UTC)

I think it works for me. I haven't compared it to the current one yet, but go for it as far as I'm concerned. —Eewilson (talk) 21:54, 19 February 2021 (UTC)

"Flowering head" same as "flower head"?

Is the cauliflower's "flowering head" similar to this definition of "flower head"? kupirijo (talk) 14:00, 8 July 2022 (UTC)

Late reply - well no, not in this sense. A cauliflower is an inflorescence in bud, yet to be formed. They grow into racemes. Pcrooker (talk) 23:38, 23 December 2022 (UTC)