1. SEEDLESS VASCULAR PLANTS
Packet #70
Chapter #29

2. THE THEORY OF EVOLUTION CONNECTION
Seedless vascular plants arose in the Carboniferous Period 420 – 360 mya
Phylum Rhinophyta are known as the oldest seedless vascular plants
These organisms left relics, fossils and coals
Scientists believe that seed plants were present during this evolutionary time period but were not dominant.
Seedless vascular plants became important as the swamps dried up and the global climate cooled.

3. TYPES OF SEEDLESS VASCULAR PLANTS
There are four phyla of seedless vascular plants.
Phylum Polypodiophyta
Ferns
Phylum Psilotophyta
Whisk ferns
Phylum Equisetophyta
Horsetail
Phylum Lycophyta
Club Mosses

4. IMPORTANT INFORMATION FOR VASCULAR PLANTS

5. LEAVES OF VASCULAR PLANTS
Microphylls
There are two types of leaves that may be found on seedless vascular plants
Microphylls
Small and have a single vascular strand
Club mosses
Megaphylls
Larger and have more than one vascular strand
Plants needed a flattened blade with more stomata for gas exchange
Ferns, horsetails and seed plants
Microphylls are thought to have evolved as extensions of stems
Megaphylls are thought to have evolved from stem branchings that filled in with an additional webbing and perhaps in response to decreases in carbon dioxide

6. KEYWORDS OF VASCULAR PLANTS
Homospory
The production of one kind of spore
Bryophytes
Whisk ferns
Horsetails
Most club mosses
Most ferns
Spore gives rise to gametophyte plants that produce both egg and sperm cells.

7. KEYWORDS OF VASCULAR PLANTS II
Heterospory
Production of two kinds of spores
Microspores
Give rise to male gametophytes that produce sperm cells
Megaspores
Give rise to female gametophytes that produce eggs.
Occurs in
Certain club mosses
Certain ferns
ALL SEED PLANTS.
The “evolution” of heterospory was an essential step in the evolution of seeds.

8. SEED VASCULAR PLANTS—FERNS

9. PHYLUM PTEROPHYTA SUBPHYLUM POLYPOIOPHYTA THE FERNS
Largest and most diverse group of seedless vascular plants.
Have xylem and phloem tissue
Most have true roots
More than 12,000 species have been described.

10. PHYLUM PTEROPHYTA SUBPHYLUM POLYPOIOPHYTA THE FERNS
Almost all species are homosporous
All have megaphylls.
Found primarily in moist tropical habitats
Few are aquatic

11. Comparison to Bryophytes
FERNS FEATURES THAT DISTINGUISH FERNS AND OTHER SEEDLESS VASCULAR PLANTS FROM ALGAE AND BRYOPHYTES.
Comparison to Bryophytes
Ferns have vascular tissue
Ferns have a dominant sporophyte generation.
As in bryophytes, reproduction in ferns depends on water as a transport medium for their motile sperm cells.
What are the similarities between the bryophytes and the seedless vascular plants (ferns)?

12. REPRODUCTIVE CYCLE OF FERNS

13. PHYLUM PTEROPHYTA SUBPHYLUM POLYPOIOPHYTA THE FERNS
Figure Page 585
Ferns display alternation of generation and they have a dominant sporophyte generation
Fern bodies consist of a rhizome (an underground stem), roots, and leaves (megaphylls).

14. PHYLUM PTEROPHYTA SUBPHYLUM POLYPOIOPHYTA THE FERNS
Sprophytes have roots, rhizomes and leaves that are megaphylls.
Leaves, or fronds, bear sporangia in clusters called sori.
Meiosis of sporangia produces haploid spores.

15. PHYLUM PTEROPHYTA SUBPHYLUM POLYPOIOPHYTA THE FERNS
Spore germinates and grow via mitosis into a gametophyte called haploid prothallus.
Heart shaped and lacks vascular tissue
Anchored by rhizoids
Bears antheridia and archegonia
Water is still required for transportation of the flagellated sperm to the archegonium
Zygote grows into free-living sporophyte plant.

16. SEEDLESS VASCULAR PLANTS—WHISK FERNS

17. PHYLUM PTEROPHYTA SUBPHYLUM PSILOTOPHYTA THE WHISK FERNS
Simplest vascular plants
Lack true roots and leaves
Consists of dichotomously branching rhizomes
Have erect stems.
Homosporous sporophylls.

18. SEEDLESS VASCULAR PLANTS—HORSETAILS

19. PHYLUM PTEROPHYTA SUBPHYLUM EQUISETOPHYTA THE HORSETAILS
Sporophytes have roots
Rhizomes
Aerial stems
Hollow and jointed
Leaves that are reduced megaphylls

20. SEEDLESS VASCULAR PLANTS—CLUB MOSSES

21. PHYLUM LYCOPHYTA THE CLUB MOSSES
Small plants with rhizomes and short erect branches
Extant species have true roots and leaves that are microphylls.

22. REVIEW

23. REVIEW
Students
List potential examination questions and/or here, and on following slides, based on the packet.