In article , Chris Hogg
writes
On Mon, 24 Jan 2005 19:10:27 +0000, Stewart Robert Hinsley
wrote:

In article , Richard Brooks
writes
I've got an old book (30s) entitled The Wright Encyclopaedia of Gardening
and the plant description structure is

Order: A division of the Vegetable Kingdom
Genus: A subsidiary part of the Order.
Species: A subsidiary part to the Genus.

So, are the terms different today ?


Richard.

The old concept of an Order is more like the modern concept of a Family.
Nowadays both terms are used. For example the family Rosaceae contains
apples, pears, quinces, cherries, roses, brambles, avens, cinquefoils,
meadowsweets, kerrias, spiraeas, and many other plants. The order
Rosales (sensu APG II) includes the family Rosaceae, and 8 other
families, including buckthorns, elms, hemp, mulberries and nettles.

Is DNA analysis applicable to plants? I assume it is. In which case,
did they get it right for most family classifications, or are the text
books going to have to be seriously revised?



P.F. Stevens maintains the state of the art at the Angiosperm Phylogeny
Website

http://www.mobot.org/MOBOT/research/APweb/

The APG II paper is available on the web as well, which gives a
convenient listing of families recognised by the Angiosperm Phylogeny
Group.

I think there were bigger problems with the suprafamilial levels -
Cronquist's sub-class Dilleniidae is a phantasm - than with the
composition of families, but there's been a fair bit of redrawing of
family boundaries, and the odd group has been found to be misplaced.

The internal classification of Rosaceae was flawed, but as far as I can
tell, no one has produced a corrected classification yet. Maloideae and
Amygdaloideae were natural groups, but it's more convenient to extend
their circumscription somewhat. A large chunk (excluding Kerrieae
(Kerria and related genera) and the nitrogen fixing members of the old
Dryadeae) of the old Rosoideae is also a natural group, but Spiraeoideae
is not.

The maples (Aceraceae) and horse chestnuts (Hippocastanaceae) have been
sunk in the mostly tropical Sapindaceae. I've looked at the DNA data
myself, and one count retain Aceraceae and Hippocastanceae if relatively
small chunks were cut out of Sapindaceae (e.g. Koelreuteria).

There's been quite a bit of shuffling around Malvaceae and Tiliaceae.
I've got a bit of material about this at

http://www.malvaceae.info/Classification/overview.html

(which I'm in the process of revising in the light of a 2004 paper).
--
Stewart Robert Hinsley