I see that I offered the term "continuum" and others the word "cline"; both
are used, but "cline" is probably more current.
This is probably a useful time to recycle a bit I have periodically
performed, mostly on Alpine-L, regarding plant names. Usually it's provoked
by discussions of pronunciation, but usage also falls within the field of
linguistics and particularly of lexicography, and of editing, disciplines
I've worked in for a long time.
In conversation, a word is "correct" if a significant set of likely
interlocutors (people you're talking with) understand what you mean. That
is, it's right if it works the way you want it to. Correctness in this
sense becomes more restricted if you are addressing an audience whose
understanding you can't predict; in that case you must choose your words
more carefully, based on some kind of broad consensus. Writing,
particularly published writing, addresses the latter kind of audience in
the widest way, and so we have codified, prescriptive choices.
("Descriptive" pertains to what people actually say; "prescriptive"
pertains to what educated consensus specifies they should say.)
Editing involves identifying usages that may not be accessible to the
widest likely audience and explaining or replacing them. This is why I now
include international as well as American measurements in the Rock Garden
Quarterly, and why it's important to use taxonomic names when writing about
plants to an audience outside one's own language and indeed dialect area.
It's never wrong to ask for clarification when someone uses a common name,
especially something like "cedar," which means Juniperus in eastern North
America and Thuja or Chamaecyparis in western North America.
On the other hand, no useful purpose is served by applying prescriptive
standards to usage in contexts where these standards are unnecessary.
However annoyed you may be by the term "calla lily," pointing it out over
coffee at a local garden club meeting can have several social effects you
might not desire: (a) it redirects the topic of the conversation; (b) it
seizes the "floor" or dominant position in an unexpected way; (c) it makes
the other speaker feel inferior. It's much more tactful to model a
preferred usage, which in conversation in North America, at least, would be
"callas" and not Zantedeschia, in the hope that your interlocutor will
imitate you. In editing, this is known as a "silent correction," because
you change it without pointing it out to the writer, and the writer almost
never notices that you've done so. He just smiles happily over what a good
writer he is.
One correspondent commented on how much he dislikes the fake common names
printed in wildflower books. I despise them too and never keep them in
articles I edit. No useful purpose at all is served by calling something
"Parry's lousewort." The only set of people I know of who use such names in
conversation are some members of the Native Plant Society, and I think even
there the practice is slowly dying out. Publishers, however, often think
that no one will buy a book that doesn't include English names for every
plant, and they force authors and editors to supply these fake names.
I often write, "If you can say 'carburetor', you can say 'zauschneria',"
but maybe I'll have to change it now that we no longer have a genus
Zauschneria. I'll bet people call them that in conversation for at least
another 40 years, though. I know I will.
Jane McGary
Northwestern Oregon, USA