[Taxacom] "Tenuinucelli" clade in eudicots?

Les Watson leswatson at westnet.com.au
Mon Feb 28 22:00:10 CST 2011

Ken refers to comments in the the 1999 edition of our 'Angiosperm 
Families' package, re 'Tenuinucelli' (etc.) and the 1998 APG 
classification. An updated and improved version of these, referring to 
APG III (2009), was posted some time ago:


In addition to showing that more recent assignments in the formalized 
2009 APG classification of families lend further support to 
'Tenuinucelli' as a sound taxonomic grouping, this draws attention to 
the ease with which the data set can be used to prepare quite detailed, 
comparative group descriptions with statistical distributions of 
character states. The first (1991) edition was prepared with 
applications of this kind in mind, with special reference to anticipated 
taxonomic applications of nucleic acid sequencing.

I should point out that any startling exceptions to emerging patterns of 
character state distributions detected in this fashion should be 
interpreted in the knowledge that our 'Families' descriptions are sure 
to incorporate occasional errors; and although they are still being 
'maintained', they have not been assiduously updated in recent times.


Les Watson
10 Maitland Avenue, Little Grove, Albany WA 6330, Australia
Email (1): leswatson at westnet.com.au
Email (2): http://delta-intkey.com/contact/watson.htm
Phone: +61 (8) 98 44 4398

On 26/02/2011 11:55 AM, Kenneth Kinman wrote:
> Hi Richard,
>         Well, you clearly did not answer my question, but just criticized
> the phrasing of my question.  Okay.   So in consideration of your
> criticism, I would instead ask it a little differently.  Is their any
> strong evidence which supports a "theory" that the tenuinucellate ovules
> of Order Cornales are synapomorphic with the tenuinucellate ovules of
> euasterids?  And if so, is there any evidence supporting the theory
> (reflected in Peter Stevens' APG website)  that Order Ericales is
> actually closer to the euasterids than Order Cornales?
>          Below is the relevant part of a post by Les Watson which seems
> to indicate the view that tenuinucellate ovules are synapomorphic for
> the clade "Tenuinucelli" (inclusive of Cornales), although it does not
> address the internal phylogeny of that clade (whether Cornales or
> Ericales are closer to euasterids).  Over 11 years later, it seems
> appropriate to zero in on  which tenuinucellate group (Ericales sensu
> lato or Cornales) is the immediate sister taxon to the euasterids).
>          Unfortunately, the APG website does not seem to address either
> the evidence or theory that evaluates the possibility that Order
> Cornales could be the immediate sister taxon to the euasterids
> (exclusive of their Ericales). But admittedy, if the tenuinucellate
> ovules of  Cornales could be shown to be clearly distinct from those of
> Ericales and euasterids, then that would be a whole different matter.
> This has bothered me for several years now, and I would finally like to
> know why the APG website continues to show their clade [Ericales (sensu
> lato) + euasterids] characterized by tenuinucellate ovules, but does not
> address the fact that Cornales also have tenuinucellate ovules (which
> Watson, below, seems to believe is synapomorphic for the whole grouping
> of APG's "asterids", including both Cornales and Ericales).
>               ----------Ken
> --------------------------------------------------------
> Les Watson posted on Taxacom in 1999:
>         An update of our 'Angiosperm Families' package has been posted at
> the DELTA Web site, at
>          http://biodiversity.bio.uno.edu/delta/angio/
> This version incorporates the classification of Flowering Plant Families
> presented by The Angiosperm Phylogeny Group (APG) in Ann. Missouri Bot.
> Gard. 85, 531-553 (1998). Their classification into ordinal and
> (informal) supra-ordinal groups reflects recent, far reaching molecular
> phylogenetic studies. It has appeared without group descriptions, but
> inclusion in our package makes it easily accessible (along with earlier
> classifications) for detailed research into morphological,
> phytochemical, etc., character state correlations, and for preparing
> comparative group descriptions, via our family descriptions in
> association with Intkey and other DELTA facilities.
> The appended natural-language descriptions for the 'Asterids' and
> 'Rosids' series of the APG's 'Core Eudicots' have been generated using
> Intkey and Confor. To conserve space, they are restricted to a small
> suite of the characters showing different tendencies in these two
> groups. They exemplify the feasibility of preparing comparative
> descriptions via the present package, and the opportunities available
> for researches into intra-group variation by extended applications of
> Intkey to our descriptive data. Ordinal descriptions may be expected to
> display less intra-taxon variability than is apparent at this level.
> The SUMMARY option of Intkey generates character-state distributions for
> any grouping of families, using all the available characters or selected
> character suites. This takes no more than a minute or two for any
> grouping that is directly built into the current package, and preparing
> one for any other series of families requires only that the user first
> selects their names. Automatic conversion of the data into
> natural-language descriptions, in RTF or HTML format, may be performed
> by applying Confor to the Intkey output.
> The following tables (obtained using Intkey) also compare the APG Rosids
> and Asterids groups, our Tenuinucelli and Crassinucelli (this package,
> cf. Young and Watson 1970) and Cronquist's (1966, 1981) subclasses, in
> terms of family compositions.
> ______
>                 Tenuinucelli Crassinucelli Unassigned
> Asterids _____    98 _____      0 ______    2
> Rosids  ______     0 ____     149 ______    0
> Unassigned *1      2 _____     31 ______    2
> Unassigned *2      8 _____     90 ______    6
> _______      Asteridae Rosidae  Magnoli. Hamamel. Caryophyll. Dilleni.
> Asterids ____  46 __    29 ____ 1 _____  1 _____  0 _____ 23
> Rosids  ____   0 __    88 _____ 1 _____ 18 _____  0 _____ 42
> Unassigned *1 _  0 __    10 ____ 0 ____  2 _____ 15 _____  8
> Unassigned *2 _  0 __    25 ____ 39 ____  7 ____ 15 ____  18
> *1 APG Core Eudicot but neither Rosid nor Asterid
> *2 APG Oddment family, or basal order, or family of uncertain position
> at the highest group level; or Eudicot but not core Eudicot; or core
> Eudicot but neither Rosid nor Asterid
> The first table shows that the APG Asterids are to all intents and
> purposes the Tenuinucelli, while their Rosids are the Crassinucelli
> minus 19 families they assign to 'basal orders' and numerous others they
> leave unclassified. The Asterids also compare quite well with the
> Sympetalae (Metachlamydeae, Gamopetalae) of Nineteenth Century systems
> (e.g. Bentham and Hooker, 1883; Engler and Prantl, 1892), while the
> Rosids are recognisable as a restricted version of Engler's
> Archichlamydeae.
> By contrast, the second table shows how poorly the APG groupings compare
> with the pseudo-phylogenetic subclasses Asteridae, Rosidae, Dilleniidae,
> etc., and the two tables clearly demonstrate that 'Asterids' and
> 'Rosids' are infelicitous names. When the impending, overhauled
> classification of the Flowering Plants is formalised, it would surely be
> appropriate to acknowledge nomenclaturally the astuteness of the
> Nineteenth Century taxonomists who detected important groups without the
> benefits of embryology and molecular biology, and with little or no
> regard for evolution.
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