Holotype fragment (botany)

[Richard Pyle]

Paul van Rijckevorsel wrote:

> There is a practical reason for botanical usage. It is desirable to have
> different parts of the plant (leafs, flowers, fruits, etc) in the original
> material. These may not be present at the same time on the same
> plant, thus
> presenting problems in gathering these. When the plant is a tree, it is
> quite doable to gather these from a single individual at
> different times: a
> matter of documenting the place, nailing a numbered plaque to the
> tree, and
> returning later. However, it was disallowed to have such collections as a
> single specimen (and thus as a single type) because the same
> method applied
> to more ephemeral plants runs a substantial risk of 'mixed
> specimens' (IIRC
> there was a collector of succulent plants who really made a mess of this).
>
> So yes, there was a practical reason for this.

I don't see the fundamental difference between botany and zoology on this.
It is equally desirable to have different lifestages of a given animal taxon
(larvae, males/females, juveniles/adults, etc.) in the original material.
This is not only inconvenient, but usually impossible to do within a single
individual organism.  Thus, in zoological practice, *one* individual is
selected as the name-bearing type; and the others are regarded as
non-name-bearing material (e.g., paratypes, etc.).

Or, are you saying that there is a greater risk in botany that multiple
parts derived from what is *believed* to be the same individual may turn out
not to be so? In other words, is it a common problem in botany that a
taxonomist wants to include a full set of seasonally disparate parts, and
thus collects the parts from what is *believed* to be the same tree over
different times, but later discovers an error in that parts were actually
acquired from more than one individual (=potentially more than one taxon)?
Analagous cases in zoology can happen with syntype series or composite
specimens, but these cases are rare and are handled by the Code.

It seems to me that the only biologically-based rationale for the difference
between botanical and zoological practice is the relative frequency with
which there is substantial ambiguity in what constitutes a "single
individual organism".  This is a problem for both kingdoms, but evidently a
more frequent problem in plants than in animals.

Aloha,
Rich