Seedless vascular plants

vascular plant

1. Continuing Trends in Plant Continuing Trends in Plant
EvolutionEvolution
•Reduction of water-dependent gametophyte
•Vascular tissue – improved water/food
transport
•More efficient roots, stems, leaves
*Tissues
*Stomates
Green: all these are in sporophyte

2. Reduction of gametophyte
Specialization in sporophyte

3. Vascular tissueVascular tissue
•In sporophyte
•Interconnects all plant
organs
•Xylem - water
•Phloem - sugar

4. Complex leavesComplex leaves
•Tissues
•Stomates

5. Plant classification reviewPlant classification review
•Bryophytes – no seeds, no roots, no vascular
*Mosses, liverworts, hornworts
•Seedless, vascular plants – no seeds
*Ferns, horsetails, club mosses, whisk ferns
•Gymnosperms - seeds & cones
*Conifers, cycads, ginkgo, gnetophytes
•Flowering plants – seeds, flowers & fruits
*Primitive, Monocots, Dicots

6. Seedless Vascular PlantsSeedless Vascular Plants
•Ferns, horsetails, club mosses, whisk ferns
•Sporophyte dominant
•Gametophyte small but still tied to water
•Dominant plants from late Devonian
through early Permian
*Equatorial coal forests
•Today somewhat marginal, but successful
•Heterospory in some (next time)

8. Fern Life CycleFern Life Cycle
Gametophyte
F
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l
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a
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Sporophyte
M
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9. Fern gametophytes …
… with young sporophytes
Mature fern sporophyte …
… with clusters of sporangia

10. Whisk Fern, Psilotum

11. Club moss, Lycopodium

12. Horsetail, Equisetum

13. Carboniferous (-300 my) coal forest model