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Chapter 22: Gymnosperms - Coggle Diagram
Chapter 22: Gymnosperms
Lifecycle
independent /heteromorphic
Progymnosperms
Aneurophytales
Relictual progymnosperms
shrubs-trees up to 12m
prostele primary xylem
Archaeopteridales
trees up to 8.4m
heterosporous reproduction
Evolution of Seeds
Megasporangium
Integument
Micropyle
Pollen chamber
Pteridospermophyta: Seed Ferns
Upper Devonian Period
Evolved from Aneurophytales
Coniferophyta: Conifers
Leaf Veins
transfusion tissue
Transfusion parenchyma
Transfusion tracheids
Cones
Seed cones
Compound
Pollen Cones
Cycadophyta: Cycads
Stout trunks
Pinnately compound leaves
Typically 1-2m
Dioecious
Cycadeoidophyta: Cycadeoids
All Extinct
Ginkgophyta: Maidenhair Tree
Single living species
Gingko biloba
Gnetophyta
Gnetum
30 species
Vines / Small shrubs
Ephedra
40 species
Shrubs / bushes
Welwitschia mirabilis
2 leaves
Single species genus