1. The Seedless Vascular Plants: Ferns and Their Relatives
Chapter 21
Lecture Outline
The Seedless Vascular Plants: Ferns and Their Relatives
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2. Outline Introduction– Primitive Vascular Plants
Phylum Psilotophyta – The Whisk Ferns
Phylum Lycophyta – The Ground Pines, Spike Mosses and Quillworts
Phylum Equisetophyta – The Horsetails and Scouring Rushes
Phylum Polypodiophyta – The Ferns
Fossils

3. Introduction to Primitive Vascular Plants
Primitive Vascular plant characteristics:
Internal conducting tissue developed.
True leaves
Roots
Gametophytes are smaller .
Sporophytes are larger and dominant
Primitive: no seeds
Four phyla of seedless vascular plants: Psilotophyta, Lycophyta, Equisetophyta, Polypodiophyta

4. Introduction Psilotophyta Lycophyta
Sporophytes have neither true leaves, nor roots.
Stems and rhizomes fork evenly.
Lycophyta
Plants covered with microphylls.
Microphylls - Leaves with single vein whose trace is not associated with a leaf gap
Psilotum
Lycopodium

5. Introduction Equisetophyta Polypodiophyta
Sporophytes have ribbed stems containing silica.
Have whorled, scalelike microphylls that lack chlorophyll
Polypodiophyta
Sporophytes have megaphylls that are often large and much divided.
Megaphylls - Leaves with more than one vein and a leaf trace associated with leaf gap
Equisetum
A fern

6. Phylum Equisetophyta – The Horsetails and Scouring Rushes
Equisetum
SPOROPHYTE:
Branched and unbranched forms, usually less than 1.3 meters tall
Stems jointed and ribbed.
Green and do Photosynthesis
If branched, then branches in whorls.
Long-lived
Branched Form

7. Stomata in grooves between ribs
Silica deposits on walls of stem epidermal cells.
Un-branched Form
Stomata in grooves between ribs
Scalelike leaves in whorls at nodes = microphylls; are nonfunctional
Strobili = Non-woody Cones

8. GAMETOPHYTES
Gametophytes lobed, green, cushionlike, up to 8 mm in diameter.
Short-lived
Small
Have Archegonia &
Antheridia
- make eggs and sperm

9. Phylum Equisetophyta Equisetum reproduction:
Asexual by fragmentation of rhizomes
Sexual reproduction:
Strobili at tips of stems with sporangia produce spores.
Spores green with 4 ribbon- like elaters attached.
Aid in spore dispersal
Spores with elaters

10. -- Spores released into ____________
and grow into _______
-- Gametophytes make_____
-- Fertilization = ___________________________and produces _________

11. Phylum Equisetophyta
Equisetum reproduction:

12. Reconstruction of fossil giant horsetail, Calamites
Phylum Equisetophyta
Human and ecological relevance:
STUDENTS DO
Reconstruction of fossil giant horsetail, Calamites

13. Phylum Polypodiophyta – The Ferns
Sporophyte Structure and form:
Vary in size from tiny floating forms less than 1 cm to giant tropical tree ferns up to 25 m tall
Fern leaves are megaphylls - Referred to as fronds.
Typically divided into smaller segments

14. Phylum Polypodiophyta – The Ferns
Sporophyte is conspicuous phase.
Fronds, rhizomes, roots
Fronds first appear coiled in crozier (fiddlehead), and then unroll and expand.
Fronds often divided into segments called pinnae (singular: pinna).
Crozier

15. Phylum Polypodiophyta – The Ferns
Reproduction:
Sporangia stalked.
May be scattered on lower leaf surface, confined to margins, or found in discrete clusters called sori (singular: sorus).

16. Sorus covered by indusium
Sori may be protected by
indusia (singular: indusium).
With row of heavy-walled,
brownish cells = annulus
Annulus catapults spores out of sporangium

17. Phylum Polypodiophyta – The Ferns
Meiosis forms spores in sporangia.
GAMETOPHYTES
Spores released and grow into gametophytes called prothalli (singular: prothallus).
Prothalli are one cell thick, and have archegonia and antheridia.
Archegonia

18. Antheridia
Require external water for reproduction because: ____
Zygote develops into young sporophyte.
Gametophyte usually dies and leaves sporophyte growing independently.

19. Phylum Polypodiophyta – The Ferns
Reproduction:

20. Phylum Polypodiophyta
Human and ecological relevance:
House plants
Function well as air filters
Outdoor ornamentals
Cooked rhizomes as food
Folk medicine
Fronds used in thatching for houses.
Basketry and weaving

21. Fossils
A fossil - Any recognizable prehistoric organic object preserved from past geological ages.
Conditions of formation almost always include quick burial and an accumulation of sediments.
Hard parts more likely preserved than soft parts.

22. Review Introduction Phylum Psilotophyta – The Whisk Ferns
Phylum Lycophyta – The Ground Pines, Spike Mosses and Quillworts
Phylum Equisetophyta – The Horsetails and Scouring Rushes
Phylum Polypodiophyta – The Ferns
Fossils