Talk:Thallus

Tissue or taxon

From the references to fungi, kelp, and more, with further details at Thallophyte, it is clear that much of the significance of this term is obsolete (referring to structures which are evolutionarily different in origin, and, one imagines, different in the details of their anatomy). But does it also have a meaning which is more about the overall anatomy or function? Our article at riverweed even uses the term thalloid for a flowering plant (although I'm not sure whether that is common terminology these days). Kingdon 15:32, 8 June 2007 (UTC)

The term refers to a level of organization. That is, a plant (or alga, etc.) whose body is a thallus has no leaves, stems, etc (i.e. no vascular tissue). More generally, an organism is thalloid if there are no structures visible that resemble leaves, stems, roots. So a moss body is technically a thallus, but it is not thalloid. A riverweed is thalloid, but not technically a thallus. Duckweed is both thalloid and has a thallus (although evolutionarily reduced). --EncycloPetey 22:48, 15 November 2007 (UTC)

Differece b/w thallus and gametophyte

I just don't know the difference ! Can anbody help ? Gullupankaj (talk) 11:03, 19 February 2016 (UTC)

Merge - April 2017

It is proposed that Podetium be merged into Thallus.

• Oppose; the thallus article is a general article encompassing plants, algae, and fungi. The article on podetium is a structure peculiar to lichen morphology, and not a general feature. --EncycloPetey (talk) 02:13, 10 April 2017 (UTC)
• Support: the topic of podetium is so specialised, it will never amount to more than a dictionary definition and a couple of sentences. This is the parent article and including a section on podetium would be quite appropriate. Not all sections of an article have to be general – kelp, fungi and lichen are already briefly mentioned – and adding the specific example of podetium as a type of thallus would improve this rather short article (itself classified as "stub-class"). --RexxS (talk) 11:53, 11 April 2017 (UTC)

  But why merge it here at the general thallus article instead of with lichen, where it would be more appropriate? --EncycloPetey (talk) 13:37, 11 April 2017 (UTC)

  Presumably because a podetium is an instance of a thallus, not an instance of a lichen. Why would it be more appropriate in the lichen article than in thallus (which is in need of some more content)? --RexxS (talk) 22:19, 11 April 2017 (UTC)

  A podetium is not "an instance of a thallus", it is a structure found only on certain lichens, whose body happens to fall under the umbrella term of "thallus". Merging "podetium" into "thallus" instead of "lichen" (or "Cladonia") would be like merging "droop-nose" into "vehicle" instead of "aircraft"; the proposed target for the merge in each case is far too general, and there is a more appropriate and focused article for merging available. --EncycloPetey (talk) 23:56, 11 April 2017 (UTC)

  Podetium: "In certain lichens (e.g. Cladonia), a fruticose portion of the thallus upon which ascocarps (when present) are borne." - A Dictionary of Plant Sciences 1998, originally published by Oxford University Press 1998. There's my source for the fact that a podetium is an instance of a thallus (or at the very least, a part of it). Where's your source that it's not an instance of a thallus (which is indeed an umbrella term for these sort of structures)? Correct yourself. Merging Podetium into Lichen instead of into Thallus would be like merging Ford AJD-V6/PSA DT17 into Jaguar XF instead of Internal combustion engine: the target is bound to be more general, but it's the same kind of object. In this case, there is certainly a more appropriate and focused article for merging available – and that's Thallus. --RexxS (talk) 15:37, 12 April 2017 (UTC)

  You have confused "part of" with "instance of". A hindwing is not an "instance of" an insect body, it is "part of" one. You have also failed to note the caveat contained in the quote you cited: it is part of a thallus in certain lichens, and not a general feature of thalli in all organisms or even in all lichens. I am sorry that you do not understand your error. --EncycloPetey (talk) 16:32, 12 April 2017 (UTC)

  There's no confusion on my part and it's your inability to source any of your claims that you need to be apologising for. Again, where's your source? Look at content of the article Podetium: "A podetium (plural: podetia) is the upright secondary thallus in Cladonia lichens." – that's what you want to merge into Lichen, not Thallus? A podentium is a structure, an example of a thallus. The most appropriate place to merge it is into an article about structures, not about the organisms that bear the structures. --RexxS (talk) 22:25, 12 April 2017 (UTC)

  I am using the same source that you are, and I have pointed this out already. The only difference is that I understand what the source says, and the scope of the articles involved. A "podetium" occurs only in certain Cladonia lichens, which works out to under 300 species with this structure. A "thallus" refers to the body form of all multicellular algae (> 15,000 spp.), all bryophytes (c. 25,000 spp.), all gametophyte stages of pteridophytes (c. 12,000 spp.), all lichens (c. 20,000 spp.), etc. So, I propose merging the article about a structure found in only a single genus of lichen (possessing around 300 species) into the article about that genus of lichen, instead of merging it into an article about more than 70,000 species of organisms, of which less than half of one percent of its members have the structure. --EncycloPetey (talk) 22:57, 12 April 2017 (UTC)

  The actual difference is that you think you know it all and you actually know less than you think. Arrogance. Look back: you've only just decided to check the source and it confirms exactly what I've been telling you all along. Yes, we all know that a podetium occurs in some members of Cladonia – although it's not confined to that genus exclusively: Cladonia is only given as a common example. You want to merge it into an article, Lichen, whose scope covers all aspects of an organism: I'm telling you that it needs to be merged into an article about structures because that's what it is. Fortunately Choess has suggested Lichen growth forms, which is a much better target for merging than either Lichen or Thallus. I'm more than happy to support that suggestion, which hopefully means I won't have to listen to any more of your ignorant ad hominems. --RexxS (talk) 11:53, 13 April 2017 (UTC)

  A secondary thallus is not so much a type of thallus as a part of the entire thallus of a single lichen. I quote from Brodo, Sharnoff & Sharnoff, "Lichens of North America": "Primary Thallus: A squamulose or crustose thallus from which fructicose stalks or podetia arise as secondary components." "Podetium (Podetia): A stalk formed by a vertical extension of lower apothecial tissues...and secondarily invested with an algal layer and sometimes a cortex..." To put this in layman's terms, if you're familiar with reindeer moss and its congeners, the thallus is all of the lichen except the spore-bearing reproductive structures. The primary thallus is a little patch of fungal crust, which rapidly dies off; the "fluffy" part of reindeer moss is the secondary thallus, composed of podetia that sprout from the primary thallus. Each branch in the "fluff" is a podetium; it's a single organized part of the larger thallus. Choess (talk) 02:21, 13 April 2017 (UTC)

• I would also prefer that this not be merged to the thallus article. Lichen growth forms, for instance, has a great deal more detail than Thallus on the possible forms that a lichen thallus can take. (This article mostly describes the superficial similarities in appearance which have caused several unrelated structures to be called thalli.) Really, Lichen#Internal structure and growth forms has enough content to support a new standalone article, Lichen anatomy or something like that, which would be an ideal target for a redirect. In any case, this was generated by a class project where I've just managed to connect with the instructor and the WEF; since it's created a number of short lichen-related dicdefs, I'd rather try to clean them all up in a coordinated fashion in the near future. Choess (talk) 02:21, 13 April 2017 (UTC)
• Oppose; as per comments above. A later, broad-ranging and carefully considered set of mergers and rearrangements would be preferable. Sminthopsis84 (talk) 22:12, 19 April 2017 (UTC)

How is kelp thalloid?

This article says that kelp and all brown algae are thalloid, but kelp and many brown algae have vascular tissue. Not only that, but they have a meristoderm, similar to the phellogen and cambium of vascular plants, and of course division into leaf and stem. This seems to me a misuse of the term, but maybe I shouldn't be asking this on Wikipedia. --Eden the plant nerd (talk) 13:59, 30 May 2022 (UTC)