newbie question, why there is no trichocereus

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DaveW
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Re: newbie question, why there is no trichocereus

Post by DaveW »

There are authorities on nomenclature (the naming of plants), they are those saying which names have been validly published according to the ICBN "rules". What we are talking about here is classification which is a different matter. Classification is how you associate different plants with each other by the use of different genera, families etc. This is largely a matter of opinion based mainly in he past on what the plant or it's parts looked like (morphology). These days the chemistry of the plants is being used as well (DNA Sequencing) but this usually better proves which plants do not belong together rather than which do.

Yes Mammillaria microcarpa was invalidly published by Engelmann in 1848, so the first available name that takes precedence is Mammillaria grahamii, also published by Engelmann later in 1856. The problem is there is often a doubt as to what some of these old species were, with some later proving to belong to different genera than first thought (as with my comments elsewhere on Stenocactus and Echinofossulocactus). That is why the deposition of a type species was later brought in so later workers could consult it to find out what the original author actually meant by their species.

In the early days nurserymen could just print a name in their catalogues and it was regarded as validly published, so often the same plant got a different name in each nurseryman's catalogue. That is why the formal rules for naming were brought in, insisting they could only be validly published in recognised scientific printed journals. That rule has persisted until very recently, but now they can also be published in recognised online journals as well as printed ones.

Nomenclature therefore is a matter of "rules", but classification largely a matter of opinion, though some research may prove certain plants are unlikely to belong together. Therefore expect there to always be changes to classification in future as more and more new plants are found or genera are reorganised.
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Peterthecactusguy
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Re: newbie question, why there is no trichocereus

Post by Peterthecactusguy »

TBH while I think in the next 10-20 years we will have a much better understanding of how cacti fit together, and which ones are related to which other ones by how much (IE they are all related by a common ancestor, just like everything else) I doubt we will ever really know everything. I will find it interesting to see what the DNA stuff decides. I will be esp interested to see what some people said in the past about plants. It will be interesting to see if morphology was correct, of it there are other variables. I will say that we already know all cacti are related to each other to a certain degree. It's just people tend to get confused between having a common ancestor and not as to how much something is related to something else. That is all I will say or Daiv might get upset. ;)
Here's to you, all you insidious creatures of green..er I mean cacti.
DaveW
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Re: newbie question, why there is no trichocereus

Post by DaveW »

Even if we knew all their past relationships it would still be a matter of opinion as to where you chose to split them into different genera and how large a genus should be. The same would apply to speciation. In the end it's always fallible humans that interpret the data.
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Peterthecactusguy
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Re: newbie question, why there is no trichocereus

Post by Peterthecactusguy »

exactly Dave, the idea is that we are constantly splitting them and merging them, but we are humans. The plants sure dont care what they are called ;)
Here's to you, all you insidious creatures of green..er I mean cacti.
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leland
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Re: newbie question, why there is no trichocereus

Post by leland »

First, as new research is done scientists change the names of some plants to reflect THEIR SCIENTIFIC OPINION of the research data. If it is named according to the rules botanists have established and published in a scientific journal that will be the ``scientific name``for the foreseeable future. NCL has the advantage that it is a group work, but even they have differences within the foremost experts in the field. However, nurserymen and hobbyists don`t necessarily want to change familiar names, especially when during their lifetime they have seen some species change names several times.

Another thing I have noticed trying to sort out the native plants of one part of Central America, is that the scientific names were often given by different botanists at different times in different countries and in different languages (this applies to the descriptions, not the Latin name). With time, it seems that some of these different species are being combined into one scientific name as further research finds that their is not enough difference between a plant found in Mexico and another plant found in Central America to justify 2 different names. Maybe they are 2 different subspecies or maybe they are the exact same plant growing under different conditions of soil. sun, etc. Or maybe the latest scientific opinion is a little off and it will change again!

Anyway, the practical approach is to use the name that is the most up-to-date, but cross reference it with the name in most common use. That is the approach I have taken on my website (round icon on the right of your screen). And keep flexible.

Another problem with the print books is that they have grown in size and become quite expensive and are usually only printed in one or 2 languages. so many amateurs and professionals do not have access to them and in that circumstance will tend to stick to the old names. Even CITES lists often have duplicate or outdated names on them, and these are the lists that government branches use for environment planning and customs inspections.
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