Paleodicots
2774190
226023016
2008-07-16T14:08:44Z
Kingdon
668610
seems like a job for the paraphyletic group template
{{Paraphyletic group
| name = Paleodicots
| image = Nymphaea alba close up.jpg
| image_width = 250px
| image_caption = ''Nymphaea alba'', from the [[Nymphaeales]]
| regnum = [[Plant]]ae
| divisio = [[Flowering plant|Magnoliophyta]]
| included =
*[[magnoliid]]
*''[[Amborella]]''
*[[Nymphaeales]]
*[[Austrobaileyales]]
*[[Chloranthales]]
*''[[Ceratophyllum]]''
| excluded =
*[[eudicot]]
*[[Monocotyledon|monocot]]
| subdivision_ranks = [[Order (biology)|Orders]]
| subdivision =
See text.
}}
'''Paleodicots''' (sometimes spelled "palaeodicots") is an informal name used by botanists (Spichiger & Savolainen 1997, Leitch et al. 1998) to refer to a group of [[flowering plant]]s traditionally considered [[dicotyledon]]s but excluded from the monophyletic group [[eudicots]] in classifications based on [[molecular systematics]].
Molecular phylogenies have shown that within the flowering plants ('''[[angiosperms]]'''), there are two major [[clade]]s, recognized in the [[APG II]] system as the '''[[monocots]]''' and the '''[[eudicots]]''' ('''tricolpates''' in some references). Both are [[monophyletic]] groups. The majority of plants traditionally recognized as "dicots" fall within the eudicot clade, but there is a non-monophyletic residue of early-diverging groups included in the [[dicots]] in older systems (e.g., the [[Cronquist system]]). These early-diverging dicots have been dubbed the "paleodicots" and correspond to [[Magnoliidae]] sensu Cronquist 1981 (minus Ranunculales and Papaverales) and to [[Magnoliidae]] sensu Takhtajan 1980 (Spichiger & Savolainen 1997). Some of the paleodicots share apparently plesiomorphic characters with monocots, e.g., scattered vascular bundles, trimerous flowers, and non-tricolpate [[pollen]].
The "paleodicots" are not a monophyletic group and the term has not been widely adopted. The APG II system does not recognize a group called "paleodicots" but assigns these early-diverging dicots to several orders and unplaced families: [[Amborellaceae]], [[Nymphaeaceae]] (including [[Cabombaceae]]), [[Austrobaileyales]], [[Ceratophyllales]] (not included among the "paleodicots" by Leitch et al. 1998), [[Chloranthaceae]], and the [[magnoliid]] clade (orders [[Canellales]], [[Piperales]], [[Laurales]], and [[Magnoliales]]). Subsequent research has added [[Hydatellaceae]] to the paleodicots.
==References==
*Leitch, I. J., M. W. Chase, and M. D. Bennett. 1998. Phylogenetic analysis of DNA C-values provides evidence for a small ancestral genome size in flowering plants. ''Annals of Botany'' 82 (Suppl. A): 85-94.
*Rudolphe Spichiger & Vincent Savolainen. 1997. Present state of Angiospermae phylogeny. ''Candollea'' 52: 435-455 ([http://www.ville-ge.ch/cjb/recherche/angiophy/angiophy.html text]).
[[Category:Angiosperms]]
[[Category:plant taxonomy]]
[[de:Einfurchenpollen-Zweikeimblättrige]]
[[es:Palaeodicots]]
[[he:דו־פסיגיים קדומים]]
[[tr:Magnoliopsida]]
[[vi:Thực vật hai lá mầm cổ]]