Progymnosperm
| Progymnosperm Temporal range:
| |
|---|---|
| |
| Archaeopteris fossil leaves | |
Scientific classification 
| |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Class: | †Progymnospermopsida |
| Orders | |
The progymnosperms are an extinct group of woody, spore-bearing plants that is presumed to have evolved from the
pteridosperm order, the Lyginopteridales. In Late Devonian times, another group of progymnosperms gave rise to the first really large trees known as Archaeopteris. The latest surviving group of progymnosperms is the Noeggerathiales, which persisted until the end of the Permian.[4]
Other characteristics:
- Vascular cambium with unlimited growth potential is present as well as xylem and phloem.
- Ancestors of the earliest seed plants as well as the first true trees.
- Strong monopodial growth is exhibited.
- Some were homosporous.
Phylogeny
Progymnosperms are a paraphyletic grade of plants.[5][6][7]
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Progymnosperms |
References
- ^ Stewart WN, Rothwell GW (1993). Paleobiology and the evolution of plants. Cambridge University Press. p. 521pp.
- S2CID 131163187.
- ^ Serlin BS, Banks HP (1979). "Morphology and anatomy of Aneurophyton, a progymnosperm from the Late Devonian of New York". Palaeontographica Americana. 8: 343–359.
- PMID 33836571.
- PMID 21652317.
- ISBN 978-1329874008.
- PMID 33836571.
External links
- Progymnospermophyta Archived 2015-04-02 at the Wayback Machine
- Botany: an introduction to plant biology