Plant Taxonomy question-Changing the rank Please help

Discussion in 'Plants: Nomenclature and Taxonomy' started by rocklee, Jan 31, 2007.

  1. rocklee

    rocklee Member

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    baton rouge
    I have a question that for hw and its been bugging me to death.

    The question is-to give the correct species name after the change of rank.

    Change the rank of

    Prunus americana var. lanata Sudw. to a species of Prunus.

    So we're moving the genus prunus to species, but how does this affect the name? i don't understand, please help if you know.
  2. pierrot

    pierrot Active Member 10 Years

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    British Columbia
    Hello rocklee

    I may be wrong here but I think what is happening is they have found that Prunus americana var. lanata is a synonym for an older name

    Rosaceae Prunus lanata ( Sudw. ) Mack. & Bush
    nomenclatural synonym: Rosaceae Prunus americana Marshall var. lanata Sudw. U.S.D.A. Forest Div. Bull. 14: 237. 1897 Based on description of P. americana, var. mollis Torr. & Gray

    from this link

    I don't think they are placing Prunus as a species instead they are ressurecting Prunus lanata as a true species instead of a variety base on the description given.
  3. Eric La Fountaine

    Eric La Fountaine Contributor Forums Moderator 10 Years

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    sw USA
    Hello rocklee,

    Yes indeed Prunus americana var. lanata has been reclassified. I am not sure I would call it Prunus lanata if I had to label the plant in the garden though. I would need to research it fully, but think I would lean toward another name I found using the databases in the following link:

    Try a few searches and I think you will find the right answer. We are willing to help with homework, but we don't want to answer study questions directly. It would defeat the purpose of homework.

    I would normally close the thread, because you said it is homework, but I think we can all agree to help you without answering the question for you and this may result in some interesting posts.

    Good luck on your studies!
  4. TonyR

    TonyR Active Member

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    Sydney, Australia
    Seven weeks of silence have followed Eric's closing remark that "this may result in some interesting posts." So I'll just offer this observation.

    Ranking of a taxon, which presumably represents an entity in nature, or a scientific concept if you like, is a matter of botanical judgment rather than of application of any set of rules. This point escapes many people.

    However, once a rank is decided, or maybe a decision made to reclassify a plant under a different genus, then what name should be used depends on application of International Code of Botanical Nomenclature (ICBN). One of its foremost principles is priority of name, i.e. the earliest-published name takes priority. There are a number of qualifications to this principle.

    Priority is only granted to names published at the same rank as the name in question. In the case of species and variety and other ranks below genus it is the epithet that counts -- an epithet is a name that cannot stand alone but only in combination with a genus name (or species name in the case of a var., subsp. etc). So if Prunus americana var. lanata was the earliest name published for this entity, and some botanist later decides that it merits species rank, there is no obligation for him/her to use the epithet lanata for that species. In practice most do, publishing what is known as a new combination for the epithet. But if there exists an earlier name for it at species rank (earlier than the new combination that is), then that name must be used.

    Look at entries for P. americana in the USDA PLANTS database and you'll find the name now accepted. If you want to understand the reasons, you will need to establish the dates of publication and whether validly published. The IPNI database will usually yield the dates at least.

    The ICBN and IPNI are available online.
  5. hortfreak

    hortfreak Active Member Maple Society

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    Prince Edward County, Ontario, Canada
    Frankly my head is spinning from all the taxonomic changes in recent years. I find more and more I have to check names to make sure I am using the current proper name. I prefer to think it is the number of changes and not age that causes this.

    For me, of all the work currently being undertaken, DNA testing is the most beneficial. Hopefully all the cultivars will be whittled to truly different cultivars and the unethical practice of some growers of changing a cultivar name (so they can claim a new introduction) will cease.

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