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Wed, 19 Nov 2008 09:06:30 PST
Mary Sue,
Rest assured, the scheme will change again in future as new data is sifted
and new understandings-- and opinions-- are garnered. A look at the *old*
literature shows that frequently what we think of as shocking new proposals
are merely resurrections of (nearly) forgotten ideas.

The problem of the legumes, a natural group if there ever was one, is a
relatively simple example. Is it comprised of three subfamilies
(caesalpinioids, faboids, mimosoids)-- or is each of these a family in its
own right? Do such questions matter much? To who? At a certain point of
fineness there is a loss of stability or durability in classification, with
regard to ranking groups especially. Some profound changes do "catch on" and
are very useful, such as Dahlgren's splitting up of the lily family in the
old and very broad sense. The same seems to be true with recent re-workings
of Malvaceae and Scrophulariaceae. If these changes are mainly induced by
molecular evidence then hobbyists may have little chance of grasping the new
classifications based on familiar characteristics.

The important idea here, in my view, is to help users at all levels to
recognize natural groupings of plants regardless of what name they receive
or how these names are arranged. Thanks to the intrepid work of Alan Meerow
an others we know the amaryllids are a natural, monophyletic group, so is
Agapanthus by itself and so too the onions and also Themidaceae (Milla,
Brodiaea, etc.). There is good cause and good evidence for recognizing each
of these as a stand alone group at some level, and it is also possible to
justify merging them all into one family (plus others) depending on how that
evidence is put to use.

Botanists will be forever arranging and rearranging these units, and the
units themselves may change, but we can still recognize many natural groups
without undue worry about how they fit in the scheme of things. We need to
know where to find the things we need in the grocery in a predictable way;
we don't need to know the whole layout of the store and what the manager is
thinking about every item.

Dylan Hannon

On Wed, Nov 19, 2008 at 7:55 AM, Mary Sue Ittner <> wrote:

> Nhu asked about why Sternbergia was included in Alliaceae in the article
> Jim noted about Sternbergia. That is because the Angiospermy Phylogeny
> Group (2003) proposed sinking Amaryllidaceae and Agapanthaceae  into
> Alliaceae. You will note if you check the Kew monocot world check list for
> family listings that this list uses the suggested alternatives so all the
> genera that were once in Amaryllidaceae are now listed in Alliaceae.
> Another example is the alternative placement by APG  (2003) in Asparagaceae
> of Agavaceae, Anthericaceae, Hyacinthaceae, and Themidaceae. If you look up
> any genus in the Kew list that used to be in one of those families you now
> find them listed in Asparagaceae. This makes for some giant families. It's
> hard for me to think how Brodiaea, Lachenalia, Pasithea, Agave and
> Asparagus are alike enough to all be in the same family. For those of us
> who consider ourselves gardeners, not botanists, it means that there is no
> real advantage in learning the different families and which genera are now
> included in them since those definitions have become so broad.
> Mary Sue
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