HERB - Nomenclature (got long)

[Kathleen Keeler]

Christine A Seelye-King wrote:

> Ok, here is a topic I would like to explore.  This comment about the
> lilac variety vs. species got me thinking about this, which I have been
> doing lately.  I would like to become much more familiar with the
> classifications of plants, and some general discussion here will work
> wonders, I think.

I'll take a first swipe at this.
Caveat:  I use plant names as an ecologist and biology teacher, not a specialist
on naming things.

> I take it a variety is one step below a species?

yes.
In biology generally, species is the minimum natural unit. Members of a species
can mate, members of the next higher unit (genus, plural genera) cannot. [Don't
get literal: two human females cannot mate but are the same species.] That's the
Biological Species Concept.
For plants, ability to cross (mate) is not as useful as in some other groups, but
the general idea holds.  Consequently  members of a species are able to cross and
similar in the way they look (act, smell, taste, whatever) because they are
closely related.
  Varieties, also called races, geographic races, ecological races and subspecies
(all equal terms at the level of academic biology) are members of the species that
you can tell apart some way.

> Are there 'points of
> difference' as in heraldry that says that something is different, but not
> different enough to be considered a separate species?

They are NOT species if they make healthy, fertile offspring when crossed (and did
so before being transplanted to gardens--plants in gardens and animals in zoos
make odd crosses--lions and tigers can and do cross in captivity).
What it takes to recognize a variety depends on the subfield I think--
for wild plants, a geographic variant that is distinctive--the dwarf coastal form
vs the inland taller type
    the one from the northern part of the range that has reddish flowers and is
hairy vs the southern yellower,
        hairless form.
for horticulture, someone else will have to answer.  I think you register it and
it becomes a variety.

I deleted more of what Christiana quoted of mine.

>   And from me again...
>         So, is that why I find garlic and other alliums listed as Liliaceae and
> as Alliaceae?

Oh yes, this. Arghhhh!

Species are basically "real" things--you aren't going to get garlic to cross with
basil.

But every higher category is human organization.  Thus: are all the things that
smell minty members of the same genus (_Mentha_) or several genera (note that
bergamot is _Monarda_ tho it has square stems and smells minty.) ?
Modern taxonomy is trying to arrange the hierarchy so that currently-crossing
things are in the same species, recently separated things in the same genus (all
the _Mentha_ species are in the genus _Mentha_) and things that are related but
not as closely, all the mints for example, are in the same family, Lamiaceae.
But at every step above species, its a judgement call:  should this be two genera
or only one?  We could lump _Monarda_ into _Mentha_.  That's why you can find
ground ivy as _Nepeta hederacea_ or _Glecoma hederacea_ :  somebody lumped it with
catnip (_Nepeta_) somebody else gave it a separate genus (_Glecoma_).  Likewise
the New Oxford Book of Food Plants (1997) gives chamomile as _Anthemis nobilis_
but lists _Chamaemelum nobilis_ as a synonym and splits German chamomile as
_Matricaria recutica_ .  You can lump Roman and German chamomile in one genus, or
you can decide they are too different and should be two genera.

Allicaceae vs Liliaceae is the same situation at a higher level:  should the
onions be part of the lily family, or are they different enough to merit a family
all their own?

>  And what and when was the Botanical Congress?

Botanical Congresses happen about every 4 years. The idea is that at that meeting
there's an official session of a worldwide group of plant taxonomists, and they
vote yes or no on proposed changes.  The next one is in June (same time as the War
of the Lilies in Calontir I believe) in St. Louis.  I'm sure there's a long list
of nomenclatural items to consider.

However, the official organizations don't so much determine names as rules for
names.  So they voted on -ceae being the ending, but not on how many families
there are.  You can find systems of plant classification with from 387 to 440
families (and those are respectable alternatives vs extremist "lumpers" or
"splitters.")

Floras like Flora of North America, Flora of the Great Plains, usually list
synonyms of plant names (like former species name for _Monarda citriodora_ was _M.
dispersa_, or _Matricaria matricariodes_ was _Chamomilla suaveolens_ (often in
some distinctive typeface) so a more recent one will usually cue you into what it
was historically called.

However, there are no name-senates ruling particular names illegal.  The process
is:  a taxonomist looks carefully at all the members of a group ("taxon") and
counts and measures and considers. Then he/she publishes conclusions in particular
journals with titles like "New Genus, _Matricaria_ (Asteraceae)" in which his/her
data, logic and conclusions are described in detail.  Other members of the
taxonomic community read the paper.  If they are convinced, they use the new names
in their own publications.  If they are outraged, they publish counter-arguments.
If they are just unimpressed, they go on using the old names.  So old names go
away because people quit using them, they aren't specifically banned in any way.

    Some names are changed because there are rules about which name should be used
when two people publish a new name for the same plant (other things being equal,
the older one), and occassionally someone makes a correction of botanical grammar
(you'll see the prairie grass as _Andropogon gerardi_ and _Andropogon gerardii_.
It turns out that _gerardii_ is the proper Latin spelling ), so its easy to choose
and people quickly switch to the more proper name.  But where its a judgement call
(how different are the onions?) each person when speaking or publishing has to
choose which name to use.  You can make personal choices -- "I think making a new
family just make more names to remember, so I'll ignore 'Alliaceae'" -- or you can
find an authority and go with them.  For example, I'm going to do whatever the New
Oxford Book of Food Plants 1997 edition does -- they worried about it for me.
They use Alliaceae, so I'll use that.  Any other widely available reference book
will do as an authority, just let people know that's your method.

   Do notice that most plants aren't a problem.

I hope that helped.

Agnes

Mistress Agnes deLanvallei, Mag Mor, Calontir.  Dedicated to promoting to the
study and safe recreation of Medieval uses of plants.  If I can assist in your
investigations, I'd be honored.

And so thanks for asking. ;-)

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