The first flowering plants
1.
2.
3.
4.
5.
The most primitive living angiosperms
The shared primitive characters
Fossils of the most primitive angiosperms
Living sister groups
Extinct sister groups
General Angiosperm Relations --- Soltis et al. 2008
Amborella
Amborella - flowers
Amborella
Amborella
Nymphaea
Nymphaea
Nymphaea
Hydatella
Austrobaileya blooming liana at UVM
Austrobaileya flowers
native to Queensland, northeastern
Australia
The first flowering plants
1.
2.
3.
4.
5.
The most primitive living angiosperms
The shared primitive characters
Fossils of the most primitive angiosperms
Living sister groups
Extinct sister groups
Inferred ancestral features of angiosperms (from living groups)
1)
2)
3)
4)
5)
6)
more than two whorls (or series) of tepals and stamens
stamens with protruding adaxial or lateral pollen sacs
several free, ascidiate carpels closed by secretion
extended stigma
extragynoecial compitum
one or several ventral pendent ovule(s)
equivocal:
1) bisexual vs. unisexual fl owers
2) whorled vs. helical attachment to receptacle
3) presence vs. absence of tepal differentiation
4) anatropous vs. orthotropous ovules.
Simple flowers of the basal groups are reduced rather than
primitively simple.
Endress and Doyle 2009
Distribution
of ascidiate
carpels
Trimenia has ascidiate carpels.
And the pistils of
Amborella are taken as
simple, ascidiate carpels.
The gynoecium of Myristica arises as a single ascidiate carpel, then
develops a cleft.
Endress’s sequence of evolution of the early angiosperm carpel.
Secretion in blue, post-genital fusion in red.
Amborella
Amborellaceae
Austrobaileya
Austrobaileyaceae
Asimina
Annonaceae
Nymphaea
Nymphaeaceae
Myristica
Myristicaceae
So what the heck is an extragynoecial compitum?
Major changes in
flower morphology
(and most primitive
states)
The first flowering plants
1.
2.
3.
4.
5.
The most primitive living angiosperms
The shared primitive characters
Fossils of the most primitive angiosperms
Living sister groups
Extinct sister groups
The Cretaceous
Archaefructus – early Aptian
(124my) Nymphaeales
First angiosperm fossils --- in phylogenetic context
from Doyle and Endress, 2010
First angiosperm fossils --- sequence of diversification
from Doyle and Endress, 2010
The first flowering plants
1.
2.
3.
4.
5.
The most primitive living angiosperms
The shared primitive characters
Fossils of the most primitive angiosperms
Living sister groups
Extinct sister groups
Gnetum
The first flowering plants
1.
2.
3.
4.
5.
The most primitive living angiosperms
The shared primitive characters
Fossils of the most primitive angiosperms
Living sister groups
Extinct sister groups
Glossopteris
Pentaxylon
Bennetitales: Cycadeoidea
Bennetitales: Williamsonia
Caytonia
So, Bailey’s plicate (conduplicate) carpel may be a
valid inference based on the Magnoliid carpel, but
derived from a plicate carpel.
Bailey’s
drawings of
carpels from
the
Winteraceae,
Magnoliids
The first flowering plants
1.
2.
3.
4.
5.
The most primitive living angiosperms
The shared primitive characters
Fossils of the most primitive angiosperms
Living sister groups
Extinct sister groups
Extra slides
Peltaspermum
Callistophyton
FLOWER FORM AND
MOLECULAR
DEVELOPMENT
(A) Classic ABCE model
(A)Evolution of MADS genes
(I) ABC model developed for
core eudicots
(II)“shifting boundary model”
applied to some basal
eudicots and monocots
(III) “fading borders”model
proposed for basal
angiosperms
Ascidiate carpels with an extragynoecial compitum…..
compitum: a tract of transmission tissue in the gynoecium that is common to
all the carpels of the one flower and that allows pollen landing on any one
stigma or part of a stigma to fertilise ovules in any carpel
Plicate carpels.