In article , Kay Easton
writes
But what I was asking you is are you aware of any greater taxonomic
confusion among the brassicas than among other plants (other, of course,
than the problem of common names which have never attempted to mirror
taxonomy and which may be used by different parts of the country to
refer to different plants)

They also vary from country to country. The point I have already made is
that whatever the common name of a plant may be, or for that matter
whatever its taxonomic name is, a gardener needs to know which plant
family it belongs to in order to carry out correct crop rotations.

A new system of classification could take the opportunity of making that
a lot more clear than it presently is. Brassicas are more relevant in
that respect because they collectively tend to take the highest
proportion of area in an average vegetable plot, and they have the
greatest number of varieties within their family compared to other
vegetables. They are also susceptible to club root if grown too often in
the same place or too intensively, and that horrible disease can take up
to nine years to eradicate.
--
Alan & Joan Gould - North Lincs.