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Re: Identification required Sat 17 Jun

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  • Anthony Pigott
    Christopher (and everyone) I m not sure that this is really the place for a full discussion on the subject (people may get bored and detailed argument can end
    Message 1 of 10 , Jul 3, 2006
      Christopher (and everyone)

      I'm not sure that this is really the place for a full discussion on
      the subject (people may get bored and detailed argument can end up
      looking a bit like 'Punch & Judy!) but let me answer some of your
      points:

      I think the use of the term 'morphotype' is not that uncommon in
      botany though it is, of course, not standard formal botanical
      nomenclature.

      A morphotype is a taxon, I agree. However, I don't think it would be
      as meaningful to refer to 'taxon convexa'. I'm not sure about the
      original use of the term, but the way I and others have used it
      recently is to mean a morphological 'form' or perhaps 'a group of
      individuals which can be distinguished on the basis of their
      morphology'. (That's not meant to be a rigorous definition.)

      The use of morphotypes is not meant in any way to replace or be an
      long-term alternative to the usual hierarchical Linnean system. It is
      used to enable 'handles' to be given to apparently distinct
      biological entities without having to commit to a particular
      relationship implicit in an hierarchical naming system. They are just
      the tips of the morphological tree - there's no implication intended
      about how the branches connect. Think of them as vars. or (perhaps
      forma) of the 'Dryopteris affinis' complex or D. affinis in your
      original sense. Instead of 'morph. convexa', I could say 'var.
      convexa' but then in the formal system, I have to say what species
      it's 'var. convexa' of.

      When we started to use the term 'morphotype' (about fifteen years ago
      now) the most widely used scheme was the one based on your original
      classification with one species and several subspecies and varieties.
      Many people found this unsatisfactory as there was good evidence for
      there being at least three species under any reasonable natural
      species concept. However, to replace the sub-species scheme with a
      species one would have meant making a number of new combinations and
      the assignment of all the forms, morphotypes, whatever, to one or
      other of the species. As there was little evidence on which to base
      such an assignment, other than subjective comparison of morphology,
      some of us decided that it would be best to use morphotypes until
      there was some hard evidence available, e.g. molecular, chemical or
      even quantitative morphology. At the time it was hoped that such
      evidence might be soon available but sadly we are little further
      forward now than we were then.

      I think the most important thing is that all the significant
      morphological forms that people are likely to come across are
      described and given some name; it matters less to me what form that
      name takes whether morphotype, var., or (micro-)species which is what
      some people advocate. If all the variation is held to be represented
      by a small number of taxa, whether sub-species or species, then one
      gets a number of problems: the taxa are difficult to describe because
      they contain a number of disparate elements, people are tempted to
      assign everything they find to one or other of these taxa, with
      consequent loss of information and specimens will be mis-identified:
      the classic example is that of paleaceo-lobata which is regularly
      keyed out as cambrensis by non-specialists.

      I agree that it is important to try to 'fix' the meaning of the
      morphotype names. To that end I have tried to give detailed
      comparative descriptions and I intend to supplement that this year
      with corresponding detailed photographic / scanned illustrations.
      Though obviously critical to the formal system, type specimens can be
      something of a mixed blessing, especially when the taxonomy of a
      group is rather fluid; they often don't represent a characteristic or
      typical plant of their taxon which leads to difficulties when
      circumscriptions change and sometimes are subsequently found to
      belong to a different taxon altogether. This has happened in the past
      in the D. affinis complex.

      As to morph. convexa itself, I'm quite convinced that there is a
      clear and distinct form here. I've found it in a number of widespread
      locations and I have a number of living plants growing. They are all
      clearly very similar and clearly not affinis or paleaceo-lobata.
      Although all these taxa have some variation (especially
      environmental), I have very rarely seen anything that appeared
      intermediate. I can't comment on the fronds that you mention as I
      don't know which ones you are referring to.

      I suppose it's inevitable that when judgements are made on
      morphological similarity, people will differ. There are also
      differences in emphasis depending upon the depth of study, the
      geographical area focused on and whether living plants or herbarium
      specimens are the main source of information. Hopefully with more
      hard evidence about the nature of the variation, some of the
      differences of opinion will be cleared up one way or the other.

      As we've said before, I don't think there's much difference between
      us on this and I expect we all agree that this is a fascinating group
      of plants of which there's still a lot to learn.

      Regards and best wishes

      Anthony



      --- In uk-ferns@yahoogroups.com, "Chris Fraser-Jenkins"
      <chrisophilus@...> wrote:
      >
      > Dear Anthony,
      > Nice to see your fine photos of "morphs" - they are really
      > clear and good photos. I wonder if I could just gently suggest we
      > steer back into standard botany and instead of yet another
      > term, "morp" - call them taxa, as usual, as that is what they
      > represent? In fact, if I understood Danser's explanations
      > correctly, the term morphotype was not originally coined in quite
      > the sense it is being adapted for today, anyway. But whatever it
      > means - unnamed taxonomic entities can surely just be called taxa,
      > can't they?
      > I still feel it's a great pity to have two alternative systems
      > going along at the same time, when standard traditional taxonomy
      > does in fact cover things perfectly adequately in my opinion and
      has
      > done for years.
      > The other thing is that by calling everything a "morphotype"
      > one looses all the carefully assessed ranking and hierarchy I
      worked
      > out in great detail over the whole of Europe and W. Asia for a good
      > number of years, and I still think that has been a most unfortunate
      > loss or drop-out of information. Whether or not some of the
      > morphotypologists agree or could see those relationships, I myself
      > definitely did see them and gradually worked them out before
      > presenting the taxonomic ranking and picture - so I don't quite see
      > the value of brushing it aside into taxa of equal, if unplaced
      rank -
      > while not presenting any alternative hierarchy. i.e. why remove
      > what was published without any evidence for doing so if there's no
      > real alternative put forward?
      > About the photos I am quite sure that this "convexa" you show
      > is just one of the many very minor local forms that occur from
      place
      > to place in different regions of Europe within D. affinis subsp.
      > affinis (i.e what I used to call var. affinis before the recent
      > upgradataion of ranks to species). There are many such and there
      > are also others that are intermediate in different places, but I do
      > not myself think they are of sufficient taxonomic importance to be
      > named - if so they perhaps ought to be as "formae" (as standard
      > taxonomic nomenclature covers this situation also), but I wouldn't
      > want to try to go so far down the hierarchy as to trouble to name
      > anything that minor. I certainly don't think it ought to be up in
      > headlights as an entity of equal ranking to an affinis or a borreri
      > etc. (when named as a morphotype)!
      > In its increased toothiness it does slightly approach subsp.
      > punctata and subsp. paleaceolobata, but I would say it is still
      just
      > subsp. affinis. I myself have several times collected some
      material
      > from populations of paleaceolobata that don't have the
      > characteristic twisting to anything like such a degree as normal
      > paleaceolobata, but which are still more recognisably
      paleaceolobata
      > than these photos. And I found a previous frond of "convexa" you
      > had identified to be one of these weak paleaceolobatas, while
      > another was probably a cambrensis. A further trouble is that
      having
      > abandoned traditional taxonomy, the type system also went - so
      there
      > is no actual type-specimen of "convexa" etc. on which we can really
      > legally fix the name and thus its identity.
      > Embarassing to see I identified 3 of Steve's photos as
      different
      > things, though! Oh well, in this game blunders can occur! The
      only
      > photo of his pseudo-"crispa" I thought I could really positively
      get
      > an angle on was the one with very fluctuose pinnules etc., which
      > looked like the old cv. 'Crispa Barnes' (a definitely abnormal but
      > very attractive plant I used to have - but I'd better see the
      actual
      > mature fronds when I get over to Edinburgh in September before I
      say
      > any more about them and get into a deeper quagmire!
      > All the best from rainy Rangoon - hope to be back in Kathmandu
      > on Monday, as I'm STILL awaiting permission from the Ministry of
      > Education to go into the University and study the herbarium for the
      > Burma fern-list (standing at 600 species so far, but I reckon at
      > least 7-800 really here - as many will be apomicts I shudder to
      > imagine how many "morphotypes' one could make if that lot!!!!).
      > Cheers,
      > Chris F.-J.
      >
    • Chris Fraser-Jenkins
      Dear Anthony and all, Interesting to see your reasons for Morphotypes. I d hope this is as good a place as any to mention the conflicting views that arose from
      Message 2 of 10 , Jul 7, 2006
        Dear Anthony and all,
        Interesting to see your reasons for Morphotypes.
        I'd hope this is as good a place as any to mention the
        conflicting views that arose from the morphotype idea, as I know quite
        a lot of ferny people are interested in it in this group.
        I think basicly our approaches do differ in a few highly
        significant ways - which when carried to their logical conclusion have
        resulted in a major dichotomy with conflicting taxonomies being presented.
        These are:
        1. In the various genera I've researched I've always had to go through
        the situation of having certain dubious entities - not sure if they
        are genuinely distinct or at what level, or not sure if already named
        or not, which are not ready to publish. As this situation almost
        always arises when studying a group I just do what most botanists have
        always done while things remained undecided for them (which I think is
        your situation as described) - I just give some nick-name such as what
        I'd been calling the new Irish taxon, like "Torc 1" etc. Then I
        wouldn't publish on this with a name until I did believe from further
        study that I was in a position to understand it and to know whether it
        was new or not and of significance or not, and then, eventually where
        to place it. This is in order not to clutter up the literature with
        provisional names any more than has to happen by error or design until
        I felt confident about them.
        But the morphotype system uses what look like formal Latin names
        for what protagonists think of as dubious entities and are being
        continually used as such, "D. affinis morph. convexa" etc. - so even
        though evidently not the intention, it has created a kind of
        alternative nomenclature despite it being said to be undecided. If
        this happened for many more complex groups (as it could, especially if
        internationally) we would, as now already, create an intractable mass
        of alternative names, confusing the issue, just as I believe this did,
        though unintentionally. I would prefer that if one were undecided one
        would simply not publish any kind of names like this, or if decided
        give proper formal names in the usual hierarchies and framework of
        Botanical nomenclature.

        2. Although you say you are yourself undecided or doubtful about the
        taxa I raised, this was not so much the case with me, as after years
        of detailed and far-reaching study all over Europe and W. Asia,
        Macaronesia etc. I became familiar enough with them to feel that I did
        know what entities there were that were really significant and where
        they fitted. There was also a great deal more "Hard" or "semi-hard"
        evidence for them than is usually the case in taxonomic study
        (considering how it happens world-wide), not only did I have great
        detail and much material showing the morphological ranges of variation
        (commonly not the case in most taxonomy) and geographical ranges of
        the taxa, but also subsidiary proof, even though not "complete"
        (which, after all it isn't for 90% of named plants). I had not only
        all the 16-spore-mother-celled chromosome counts showing different
        pairing behaviour in the different entities, as listed in my
        unpublished monographic study, but also phytochemical study showing
        different chemistry for borreri and similar for the others.
        If you consider the British ferns, the great bulk are without such
        evidence and quite a few even without such detailed traditional
        taxonomic study - but lack of so-called "hard" evidence is no grounds
        for dislodging the various authors' published accounts. The
        reliability of the study depends on the ability of the various
        different authors - and from a historically retrospective viewpoint it
        became well known some were less thorough and successful than others.
        Their work has been replaced by new evidence, new studies, giving a
        new taxonomy decided upon by a later author - and that's how it goes
        on. We do not normally have the situation where an author says in
        effect, "I am not decided for myself, I feel we need more evidence,
        therefore I am going to replace the existing taxonomy, not by offering
        a new one - but by offering a list of any name at any rank, including
        some unproven new ones, and just call them all morphotypes". To me
        that is actually retrograde and offers no new findings, expertise or
        scheme to replace the old one, but creates a parallel, temporary
        system of dubious "nomenclature" and thus a nasty muddle!
        No one has actually presented any place where the taxomnomy I am
        putting forward is known to be erroneous - so it's actually just a
        positive being replaced by a negative without any evidence as to why
        it should be replaced.
        I am well aware that this was NOT the intention, as the
        morphotypes are supposed to be non-judgemental - but the practical
        result has been to replace the published and researched taxonomic
        scheme with one that is not actually decided and accepted by the
        author, but is a list saying "we don't know". Time will tell, of
        course, but I believe I DO know the things I published! I simply do
        not see the value of replacing it with what someone else says they
        don't know and which is only supposed to be temporary until some
        hypothetical time in the future when that author can say he does know.
        When you say there isn't much difference between us it is only true
        in that the morphotypologists do indeed accept the taxa I named, but
        merely say they don't know where to place them. But that is an
        important difference!

        3. Perhaps the most important difference is that I am quite convinced
        I can indeed recognise where these taxa fit. It is from that that the
        hierarchy was deduced. I deliberately distinguish between minor taxa
        and more major ones - at first I separated the major ones as
        subspecies (and I remember that at that time it was considered
        terribly over-splitting!); now after years more study I am placing
        them as species. It is also clear to me that WITHIN them there are
        certain geographical entities which are of considerable significance -
        thus these (which I originally made at the rather unsatisfactory rank
        of variety) are now subspecies. I can recognise easily from their
        morphology that subsp. kerryensis and subsp. paleaceolobata are good
        recognisable entities that obviously belong within D. affinis (in the
        new, restricted sense of the former subsp. affinis). But beyond that
        there is some much more minor and morphologically less significant
        variation that is apparently partially genetically fixed in some
        populations. To me it is natural and perfectly acceptable that there
        can be minor, part-recognisable variant forms within any fern-species
        I know - unlike the view of a computer-cladistician who says each
        species must be a single entity only and ends up with only two ranks,
        the species (actually meaning precisely what morphotype has come to
        mean) and the genus.
        That is a place we really differ, as I worked out how they are
        related from their morphology (inc. spore-size and degree of abortion
        in a few cases where the basic cytotype has not been found) and
        produced a hierarchical scheme which reflects it. I do not find it
        very satisfactory to put this aside without showing any actual errors
        in it. If, for example, D. affinis subsp. kerryensis (cytologically
        unknown) turned out to be triploid, not diploid (as its spores and
        other morphological features strongly indicate), then it should be
        published and the necessary correction made - one should not deduce
        from such a question that it indicates the whole taxonomy should be
        put aside and replaced with a list of unranked names! The vast bulk
        of taxonomic novelties have not had the luxury of even a basic
        chromosome-count, especially in the past, but also still today, let
        alone any other "hard" evidence. It is not thereby invalid or to be
        replaced by a "don't know" list of unranked names.

        4. As morphotypes are unranked this has seriously destroyed one of the
        major things I was trying to get over to others - the fact that within
        this apomictic schemozzle some variants are important and of major
        significance, some less so and obviously fitting within the others,
        and some of much less significance. Perhaps the most unsatisfactory
        result of replacing taxonomic names with morphotypes is that it simply
        places a local form or clone on the same level as a major taxon (and
        as they are apomictic even a single individual is reproductively
        isolated and acts as if a "biological species"). As morphotypes they
        are all at the same level of ignorance about their significance. I
        cannot accept that a minor local form occurring here and there
        apparently through cloning should be at the same level as D. affinis
        (as was the situation when morphotypes were first inserted into this
        equation), or as subsp. insubrica, for example.

        Overall, these various differences in approach have resulted in
        what must be admitted to be a real problem having been overlaid onto
        this group. I believe by far the better approach would have been to
        adjust the taxonomic scheme wherever an error turns up - so far none
        have that I know of since the earlier nomenclatural/typification
        adjustment I made - and I really believe now that the morphotype
        scheme has not only introduced problems unnecessarily, but has really
        had its day. In my view it was an unfortunate sideline which there is
        no longer any need for, and I know that the joint author of the
        original work also regretted having used morphotypes on later
        reflection.
        After all, if you believe "convexa" is an important taxon, then
        please do publish it now with a proper rank as an additional taxon to
        those I recognise in the paper on the D. affinis group I have recently
        submitted for publication. Let's be honest we both have a pretty good
        idea of where it does belong, don't we? It must be within D. affinis,
        you may like to have it as an additional subspecies of D. affinis; I
        would merely disagree on that point and sink it within subsp. affinis.
        In fact, when you say "Convexa" is in your opinion a distinct and
        clear form - I agree, but at that very rank! Future botanists can
        decide for themselves which treatment and rank they felt was more
        accurate and realistic. If in years to come someone goes into the
        more minor variants within subsp. affinis (which I would prefer not to
        name, but which could be varieties or better, forms) I would be able
        to recognise "f. convexa" at that lower rank along with f. disjuncta,
        f. atlantica etc. I do not assess it as being a more major taxon,
        just one of the fairly numerous form-clones, and in my view, not of
        the same rank as something like subsp. punctata or subsp.
        paleaceolobata. This sort of doubt was not any reason to replace the
        whole taxonomy entirely, with morphotypes!

        A few comments on questions raised:
        (1). Taxon is not a rank, therefore it would never have been a case of
        referring to "taxon convexa"! I believe an author should have decided
        where to place it, including at what rank, before publishing a name -
        which has become apparently formal by usage. Anyway, now, with the
        treatment of three British species, there should be no real further
        difficulty in publishing it and saying what species it might be a
        variety convexa of - as a further subspecies of D. affinis if you
        think it is worthy of that rank, or as a var. (the Code is so
        adaptable - nomenclaturally a variety is a variety of its species, not
        of its subspecies!). Incidentally what is its range in Europe - any
        idea? I think I saw it in the Schwarzwald in Germany at least, but I
        did not keep track of every variant of what I now see as subsp.
        affinis except as can be studied from my many herbarium-collections in
        NMW, BM (and FR and H).
        (2). I think the problem for most people in the earlier stages was not
        so much that there was little evidence for the taxa (there was
        actually quite a lot), but that there was quite literally little
        knowledge of the taxa. I found that many more people were unhappy
        with a single species divided into subspecies because they felt it was
        unnecessarily splitting - while only one or two people (I can list
        them on the fingers of one hand) were unhappy because they felt it an
        unnatural species-concept, most comments were quite the other way
        around. Those who didn't like it as one species were only thinking of
        it theoretically, influenced by cladistics and N. American "taxonomy",
        and had either very little or zero actual practical knowledge of the
        group at the time. It is really only after much further practical
        experience that I have come round to treating species within it, and
        for quite different reasons from the "biological species" diversion
        from taxonomic reality!
        (3). I am not sure I can agree that naming all significant forms
        people are likely to come across is so desirable or rather so
        straightforward - the key word is "significant" and the taxonomic
        insight to decide practically and meaningfully which are significant
        and which not. I believe that the two new Morphotypes, "Convexa" and
        "Insolens" are not so significant - you believe they are. So the way
        forward is for you to name them formally, then other botanists can
        decide if they accept those taxa or prefer to sink them. But I would
        be astonished if anyone wanted to sink paleaceolobata, insubrica etc.
        - but would also feel they entirely misunderstood them if they didn't
        place them within D. affinis or D. cambrensis, respectively. It would
        in my opinion be seriously foolish and display a lack of knowledge of
        the group to place them all at specific rank, too (assuming we can all
        now/very soon leave the morphotype scheme behind), but then I don't
        imagine anyone who knew the group would come to think like that.
        (4). No such problem exists as being forced to assign disparate
        elements to inappropriately few taxa. One simply identifies them to
        subspecific rank - one need not go further if one feels unable to.
        This is the beauty of standard taxonomic practice and hierarchy.
        paleaceo-lobata versus cambrensis is nothing to do with that - that is
        merely a question of misidentification from inadequate keys and
        description. That occurs in all genera and is much helped to be
        avoided by the study of authentic herbarium-specimens or guidance from
        specialists if possible.
        (5). I'm afraid any idea of "fixing" the names onto the correct thing
        can really only be done by means of types - which is why the type
        system came into existence and widespread use, despite initial
        opposition. There will surely not be any problem for YOU to select a
        type that IS representative of your concept - that should be your
        responsibility to do so! You can then help further by photographing
        the type itself in your paper. Many of the problem unrepresentative
        types of the past that you allude to were because the authors had no
        real knowledge of the genus to allow them to compare their specimen
        with related species (otherwise through destruction of types, of
        course), so chose any old specimen at random - if in the 18th C. a
        plant came from Amboyna it was called "D. amboinensis", with no
        thought to compare and contrast it with a very closely related species
        occurring in Sri Lanka as "D. zeylanica", unknown to the author!
        But this IS another of the great insufficiencies and drawbacks of
        resorting to morphotypes - there's no formal type system for an
        informal name - and even if you said it was a type, it would not have
        to be followed by anyone who decided to formalise the name.
        (6). I really do hope and plead that in any publication you may be
        planning, you do take the plunge and for once and for all tell us
        precisely what you believe your entities to be - in a formal taxonomic
        nomenclatural system. I am sure from our conversations etc. that you
        do indeed have a very good idea now as to how they are most
        appropriately placed! If it doesn't agree with what I or anyone else
        thought it doesn't matter - but I feel you really owe botanists the
        ability to assess your taxa as proper, formally ranked entities. It
        just would be such a shame to continue to hang on to these "don't
        know" morphotypes any longer - especially as I am pretty sure you DO
        know and are well able to make a decision where and how to place them!
        Then all doubts re typification and meaning of the name can be avoided.

        Somehow, I feel, we have to aim to remove the dual, opposing
        systems for dealing with the Dryopteris affinis group as quickly as
        appropriately possible - and I feel we can already do so right away.
        If not, only confusion will continue reign supreme, as it appears to
        in Britain at the present time. That is why I am quite simply
        requesting you to abandon the Morphotype system at this point, while
        continuing your publication and investigation of the group on as wide
        a scale as possible.
        Chris Fraser-Jenkins, Kathmandu.
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