Vascular Seedless Plants

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Vascular Seedless Plants
By Ravi Rao Biology 110H Dr. Heidi Appel
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Evolutionary Location
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Major Taxonomic Groups

• Psilophyta
• Whisk Ferns
• Lycophyta
• Club Mosses

• Pterophyta
• Ferns
• Sphenophyta
• Horsetails

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Major Taxonomic Groups

• Psilophyta
• Whisk Ferns
• Free-living sporophyte and gametophyte
• No leaves or roots
• Only one known genus survives today, but they
  were much more diverse in the past
• NOTE despite the name, they are not true ferns

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Major Taxonomic Groups

• Lycophyta
• Club Mosses
• Free-living sporophyte and gametophytes
• True roots, stems, and leaves
• 300MYA, these were the dominant flora with large,
  expansive swamp-forests of lycopods.

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Major Taxonomic Groups

• Sphenophyta
• Horsetails
• Free-living sporophyte and gametophyte
• Circular, ribbed stems with whorled leaves
• Again, much more diverse in the past

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Major Taxonomic Groups

• Pterophyta
• Ferns
• Stem consisting of large underground structure
  (analgous to roots) called the rhizome.
• Sori clusters of sporangia on underside of
  fronds.
• Most diverse of the vascular seedless plants
  around today

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Key Features

• Similarities
• Motile Sperm
• Required moist habitats to reproduce (similar to
  the mosses)
• Homo/Heterosporous
• Varies by taxonomic group, some lycophyta
  heterosporous (shows transition mosses
  heterosporous gametophytes)

• Differences
• Vascular Tissue
• Early evolution of leaves
• Diplo-Dominant
• Adaptation for success on land due to bombardment
  of UV radiation
• Fern Life Cycle Animation Click Here

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Interesting Facts/Importance

• Much of the coal and oil found today were formed
  from the extensive growth of these plants in the
  moist swamp forests.
• Certain societies in the less developed countries
  rely on these plants for medicines and food.
• The species Equisetum arvense Linn. demonstrates
  an affinity for gold, reffered to by the locals
  as a "gold indicator."
• The most common use of these plants in modern
  society is landscaping and erosion prevention.