Voltziales
Walchia piniformis
The Voltziales are a group of extinct seed plants. They are considered the ancestors of the extant conifers.
- 3.1 Notes and references
Features
The Voltziales are a rather heterogeneous group. In the past, a distinction was made between "volt social " conifers and " walchialen " conifers. The former are characterized by orthotropic branching, broad leaves, and short shoots with flattened, partially fused scales. The latter are branched plagiotrop, have needle-shaped leaves and short shoots bear radially arranged scales. The stomata form bands, the pollen is monosaccat.
System
Families
The two groups of "volt social " and " walchialen " Conifers are not clearly demarcated from each other and groups are now placed together in the order Voltziales. According to Taylor et al. (2009) include the following families to order:
- Utrechtiaceae
- Thucydiaceae
- Emporiaceae
- Majonicaceae
- Ullmanniaceae
- Bartheliaceae
- Ferugliocladaceae
- Buriadiaceae
The phylogenetic relationships of the different families of the two orders were reconstructed by Farjon as follows:
Thucydiaceae
Emporiaceae
Ullmanniaceae
Utrechtiaceae
Majonicaceae
Voltziaceae
Phyllocladaceae
Pararaucariaceae
Pinaceae
Cephalotaxaceae
Taxaceae
Palissyaceae
Geinitziaceae
Doliostrobaceae
Sciadopityaceae
Ferugliocladaceae
Genera incertae sedis
Some species that are not adequately known, are from Taylor et al. (2009 ) none of the families assigned ( incertae sedis ), since not even considered their assignment to the Voltziales assured. They are:
- Glyptolepis
- Conewagia
- Voltziopsis
- Florinostrobus
- Tricanolepis
- Swedenborgia
- Aethophyllum
Documents
- Thomas N. Taylor, Edith L. Taylor, Michael Krings: Paleobotany. The Biology and Evolution of Fossil Plants. Second Edition, Academic Press 2009, pp. 807ff. , ISBN 978-0-12-373972-8