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

Gen

eral

Ang

iosp

erm

Rel

atio

ns -

-- S

olti

s 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. 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

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.

AmborellaAmborellaceae

AustrobaileyaAustrobaileyaceae

NymphaeaNymphaeaceae

AsiminaAnnonaceae

MyristicaMyristicaceae

So what the heck is an extragynoecial compitum?

Major changes in flower morphology (and most primitive states)

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 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. The most primitive living angiosperms2. The shared primitive characters3. Fossils of the most primitive angiosperms4. Living sister groups5. Extinct sister groups

Gnetum

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

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. The most primitive living angiosperms2. The shared primitive characters3. Fossils of the most primitive angiosperms4. Living sister groups5. Extinct sister groups

Extra slides

Peltaspermum

Callistophyton

(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

Plicate carpels.