Seedless Vascular Plants (SVP)

Question 1

Characteristics of SVP

Answer 1

• dominated Earth ~100m years
• LIGNIN
• vasculature
• true leaves/roots; many have roots associating w fungal rhizomes
• no flowers/seeds

Question 2

SVP Phyla (4)

Answer 2

• Psilotophyta
• Lycophyta
• Equisetophyta
• Polypodiophyta

Question 3

Phylum Psilotophyta: whisk ferns

Answer 3

dominant sporophyte (2n):
- rhizomes (creeping rootstalk)
- roots scattered along rhizomes (associated w mycorrhizal fungi)
- stems have ENATIONS, tiny green non-vascularized flap of tissue

Question 4

Phylum Lycophyta: club mosses

Answer 4

• stems have MICROPHYLLS (needle-like leaves); belief: resulted from enations becoming vascularized
• several genera extinct (lignin -> fossils)
• note: rhizomes also sporophyte

Question 5

Phylum Equisetophyta (horsetails, scouring rushes)

Answer 5

• sporophyte stems joined and ribbed, silica deposits hardens stem
• strobili at stem tips house sporangia
• spores w 4 ribbon-like elaters attached help dispersal
• asexual repro (rhizome fragmentation)

Question 6

phylum polypodiophyta: ferns

Answer 6

• most successful SVP
• can grow tall
  sporophyte structure:
• MEGAPHYLLS - fronds
• fronds & roots come from rhizomes
• fronds first appear coiled in crozier (fiddlehead) then unroll

Question 7

phylum polypodiophyta: ferns - sporangia

Answer 7

sporangia on lower leaf surface, or found in clusters - sori (sing. sorus)
- sori might be protected by indusia (sing. indusium)
- annulus catapults spores out of sporangium

Question 8

phylum polypodiophyta: ferns - spores

Answer 8

spores grow into gametophyte (male AND female parts) - prothalli
- prothalli: one cell thick antheridium and archegonia
- zygote develops into young sporophyte
- gametophyte dies and sporophyte grows independently