Ferns Flashcards
When did leaves originate?
in fern ancestors
How did microphylls evolve?
- enation occurs when epidermis branches off
- develops into a microphyll when a singular vein runs into the branch
- single vein or undeveloped vein in microphylls
How did megaphylls evolve?
- when epidermis continuously branches, they become thinner
- tissues fills inbetween the branches to become megaphyll
What is evidence for leaf evolution?
transitional species
What are monilophytes?
monophyletic group, broadly known as ferns
what are leptosporangiate?
what previously named ferns, which only included the commonly seen ferns
What are whiskferns?
ferns that lack true roots and leaves
Why were whiskferns once not considered ferns?
thought to be a lycophyte due to its bifurcating system
What is an adder’s tongue?
one sterile-leaf, one fertile-spike, and roots
What is a fertile spike?
smaller leaves with a sporangium at the end of the leaf
What is a giant fern?
- large frond
- globular rhizome
What is a horsetail?
- common ornamental plant
- hollow and jointed roots, rhizomes, and aerial stems
- reduced megaphylls
What were ancient horsetails like?
- tree-shaped and large
- second tree to evolve in evolutionary history
How do horsetails disperse spores?
- wrapped in elaters
- dries, and shoots spores out
How did ferns evolve?
- all fern ancestors had leaves and roots
- possible that in some ferns, these features were lost
