Vascular Seedless Plants

1. Vascular Seedless Plants By Ravi Rao Biology 110H Dr. Heidi Appel

2. Evolutionary Location

3. Psilophyta Whisk Ferns Lycophyta Club Mosses Pterophyta Ferns Sphenophyta Horsetails Major Taxonomic Groups

4. 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

5. 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.

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

7. 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

8. 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 Key Features

9. 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.