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The first flowering plants
1. The most primitive living angiosperms2. The shared primitive characters3. Fossils of the most primitive angiosperms4. Living sister groups5. Extinct sister groups
The first flowering plants
1. The most primitive living angiosperms2. The shared primitive characters3. Fossils of the most primitive angiosperms4. Living sister groups5. Extinct sister groups
1) more than two whorls (or series) of tepals and stamens 2) stamens with protruding adaxial or lateral pollen sacs 3) several free, ascidiate carpels closed by secretion 4) extended stigma5) extragynoecial compitum6) one or several ventral pendent ovule(s)
equivocal: 1) bisexual vs. unisexual fl owers2) whorled vs. helical attachment to receptacle3) presence vs. absence of tepal differentiation4) anatropous vs. orthotropous ovules.
Simple flowers of the basal groups are reduced rather than primitively simple.
Inferred ancestral features of angiosperms (from living groups)
Endress and Doyle 2009
Endress’s sequence of evolution of the early angiosperm carpel.Secretion in blue, post-genital fusion in red.
AmborellaAmborellaceae
AustrobaileyaAustrobaileyaceae
NymphaeaNymphaeaceae
AsiminaAnnonaceae
MyristicaMyristicaceae
The first flowering plants
1. The most primitive living angiosperms2. The shared primitive characters3. Fossils of the most primitive angiosperms4. Living sister groups5. Extinct sister groups
The first flowering plants
1. The most primitive living angiosperms2. The shared primitive characters3. Fossils of the most primitive angiosperms4. Living sister groups5. Extinct sister groups
The first flowering plants
1. The most primitive living angiosperms2. The shared primitive characters3. Fossils of the most primitive angiosperms4. Living sister groups5. Extinct sister groups
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. The most primitive living angiosperms2. The shared primitive characters3. Fossils of the most primitive angiosperms4. Living sister groups5. Extinct sister groups
(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
FLOWER FORM AND MOLECULAR DEVELOPMENT
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
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