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[Joseph Laferriere]

I would very much prefer the following:

A. Leaves densely pubescent abaxially
     Leaves obtrullate    ......   X
     Leaves not obrtullate .....   Y
A. Leaves not densely pubescent abaxially
    Leaves obtrullate ..........    Z
    Leaves not obrtullate ......    A

Doing it your way is infinitely more confusing. I have seen keys with 6
or 8 characters strung together in your kind of a key, with the user
being required to match not one but all before being able to proceed to
the next leg of the key. Besides, I do not like the "obtrullate" vs. "not
obtrullate" choice. Give the reader more info on what the second
alternative is. Say "obtrullate" vs "linear" or something. This will save
the reader from having to decide on something which might be sort of
obtrullate but not quite matching the textbook definition of the term.

On Tue, 5 Sep 1995, Richard Jensen wrote:

> Well, let's consider this.  I have a group of species some of which have
> leaves densely pubescent on the abaxial surface and some of which are
> distinctly obtrullate in outline.  Only one species has both characters,
> so I argue that the following is a good couplet:
>
>       A. Leaves obtrullate and densely pubescent abaxially.....species X
>       A. Leaves not as above
>
> Yes, I could construct a key with species X keyed under both
> "characters," but the above couplet simplifies the key.
>
> Richard J. Jensen      |   E-MAIL: rjensen at saintmarys.edu
> Dept. of Biology       |   TELEPHONE: 219-284-4674
> Saint Mary's College   |   FAX: 219-284-4716
> Notre Dame, IN  46556  |
>
>