Talk:Cannabis reproduction

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[edit] Cannabis Reproduction

We can discuss Cannabis Reproduction here. There are a number of citations I would question here including the removal of other citations used. When we have this hammered out we can see if it can go back into the main article with some of it. This is a huge topic and right now there is no mandate to have a plant article with a reproduction section. See [1] This was requested at the end of [2]. Since the answer was avoided best take it to here. (Simonapro 06:25, 7 October 2006 (UTC))


[edit] Botany

Like all flowering plants, the reproductive structures of Cannabis are flowers. Cannabis has imperfect (or unisexual) flowers; the male (staminate) reproductive structures are completely separate from the female (carpellate, sometimes called pistillate) structures.

  • Again this incomplete statement excludes the hermaphrodite condition and so is wrong. As an introduction it tells us that Cannabis is not hermaphrodite. Yet we have stable hermaphrodite populations which directly contradict this statement. The original article statement which read Cannabis has two known forms of plant sexuality, dioecious and hermaphroditic or monoecious.[1] was much more accurate in that this is what cultivators are seeing and are concerned with.

Male flowers are borne on loose panicles, while female flowers are borne on racemes.[2] Dense clusters of female flowers produced by drug varieties of Cannabis are commonly call buds. All varieties of cannabis are wind-pollinated [3] and produce seeds called achenes. [4].

  • This is also an incomplete statement. Cannabis pollen can also travel by gravity without wind and is spread by other living things such as insects and animals. See [[3]]

Most varieties of Cannabis are short day plants [3], with the exception of C. sativa var ruderalis which is commonly described as "auto-flowering" and may be either day-neutral or require long days.

  • Another incomplete statement. Types of Industrial hemp are also auto-flowering.
  • This is just one example of why this section needs to be dealt with here. Simply put, it is not in a condition to warrent inclusion in the main Cannabis article especially when complete statements with citations have been removed for incomplete statements.


It is certainly the case that the term hermaphrodite is in widespread informal use among cannabis cultivators to describe the intersex condition, and this could be discussed in the article, but it should be also pointed out that the usage is imprecise because Cannabis has imperfect flowers.
Occurance of day-neutral or long day photoperiodism can also be described, with sources. Clarification of whether ruderalis is actually day-nuetral or long day would also be beneficial.
Wind-pollination is the correct term, it does not preclude gravity or insect pollination. See Pollination syndrome for additional clarification.
It should not be assumed that the primary audience for this article will be cultivators of drug-type cannabis. That would be POV.
-- Chondrite 22:30, 7 October 2006 (UTC)
You are using the term imprecise but not wrong. For example there is nothing wrong with the quote The sexual phenotype of Cannabis often shows some flexibility leading to the differentiation of hermaphrodite flowers or bisexual inflorescences (monoecious phenotype) from the paper The sexual differentiation of Cannabis sativa L.: A morphological and molecular study which can be found at [[4]].
You didn't mention any of the other methods of pollen transfer.
I am not assuming that the primary audience is a drug cultivator. (Simonapro 06:08, 8 October 2006 (UTC))


  • "Reproductive type, pollination. Plants dioecious, or monoecious (rarely). Gynoecium of male flowers absent. Pollination anemophilous." - DELTA (taxonomy) entry
  • Floral formula
  • "In Cannabis sativa, female flowers result from the direct “pass-over” from perianth initials to carpel initials; these flowers never form any vestiges of stamen initials." Dellaporta, SL and Calderon-Urrea, A (1993) "Sex Determination in Flowering Plants" The Plant Cell, 5, 1241-1251
  • "Although the hemp is a dioecious species, as a consequence of intensive improvement, a lot of sexual phenotypes are cultivated, the most frequent being the monoecious forms, classified in more categories, on a five-point scale, depending on female flowers/male flowers ratio." Truta et al 2000 (reference 13 in article)
  • "Cannabis sativa L. is a dioecious species with sexual dimorphism occurring in a late stage of plant development." V. M. Cristiana Moliterni , Luigi Cattivelli, P. Ranalli and Giuseppe Mandolino (2005) "The sexual differentiation of Cannabis sativa L.: A morphological and molecular study" Euphytica 140:1-2, 95-106
  • Moliterni et al also say: "The sexual phenotype of Cannabis often shows some flexibility leading to the differentiation of hermaphrodite flowers or bisexual inflorescences (monoecious phenotype). Sex is considered an important trait for hemp genetic improvement; therefore, the study of the mechanism of sexual differentiation is of paramount interest in hemp research." although this is not consistent with the botanical descriptions.
-- Chondrite 19:35, 8 October 2006 (UTC)


I have added information about hermaphroditism to this section, per Militerni et al (2003). It will also be useful to add the bit about how female flowers don't have vestigial stames, as from Dellaporta et al (1993), as this is ununsual in dioecious flowers. We should also add that cultivators of drug type cannabis often describe any intersex individual as a hermaphrodite, even when the individual is actually monoecious. Chondrite 18:55, 9 October 2006 (UTC)

[edit] Breeding systems

Cannabis has been described as predominantly dioecious [3] [5], although some monoecious varieties have also been described [6]

  • Let's look at what the source actually say.

Cannabis is a dioecious plant, which means that the male and female flowers develop on separate plants, although monoecious examples with both sexes on one plant are found. - Clarke. So the word some in the staement is really a POV. There are monoecious examples.

  • More importantly Clarke has confirmed that the original statement that Cannabis has two known forms of plant sexuality, dioecious and hermaphroditic or monoecious. So both Clarke and Green confirm this cited statement you removed.
  • Subdioecy (the occurance of monoecious individuals and dioecious individuals within the same population) is widespread. The first cite, Mignoni, G (1999). Cannabis as a licit crop: recent developments in Europe. United Nations Office on Drugs and Crime. Retrieved on 2006-10-05, says However, examples of monoecious plants can also be found within any given population--namely, single plants bearing both male and female inflorescence--and, furthermore, hermaphrodite inflorescence on mono-sexual plants [1]. The source cited for this is 1. F. Crescini, Piante Erbacee di Grande Coltura, (Rome, Reda, 1971), pp. 167-195. So again the term some is a POV. So the first two sources you cited would disagree with the statement that there are some monoecious varieties. (Simonapro 07:47, 7 October 2006 (UTC))


The problem with the clause "hermaphroditic or monoecious" is that it is ambiguous and suggests either that perfect flowers occur in Cannabis or that the terms monoecious and hermaphroditic are synonymous, neither of which is true.
Cannabis is described in the sources as primarily dioecious with some occurance of monoecy in populations. If the word 'some' is bothersome then it can be removed. It is not clear whether the description of intersex inflorescences is using hermaphrodite precisely or whether (as seems likely) it is used loosely to indicate the occurance of separate male and female flowers on the same inflorescence. Clear corroboration of the occurrence of perfect flowers in Cannabis from another source would be needed to confirm gyno-, andro- or trimonoecy, or trioecy in Cannabis.
Chondrite 22:48, 7 October 2006 (UTC)
Again Clarke says Cannabis is a dioecious plant, which means that the male and female flowers develop on separate plants, although monoecious examples with both sexes on one plant are found. He doesn't use the term mainly or some. Also Clarke is quite happy to use the term hermaphrodite over a hundred of times in his book Marijuana Botany. One example, ... Controlled "free" pollinations may also be made if only one pollen parent is allowed to remain in an isolated area of the field and no pollinations are caused by hermaphrodites or late-maturing staminate plants.
Also the original statement said Cannabis has two known forms of plant sexuality, dioecious and hermaphroditic or monoecious.[1] Clarke even says Hermaphrodite or monoecious plants may be isolated from the remainder of the population and allowed to freely self-pollinate if pure-breeding offspring are desired to preserve a selected trait. (Simonapro 13:05, 8 October 2006 (UTC))
It is self-contradictory to say that there are two known forms of plant sexuality, name three in the very same sentence, and discuss more than two in the article. Having no wish to misrepresent either the sources cited or the facts, I am not opposed to discussion of hermaphroditism in proper context in the article. Chondrite 19:38, 8 October 2006 (UTC)