1. UNDERSTANDING GYMNOSPERMS
JRMG

2. What are GYMNOSPERMS? gymnos - naked + spermae - seed
have seeds (not fruits or flowers)
developed (Paleozoic Era)
dominant: Mesozoic Era (early )
heterosporous seed ferns
Cone bearing plants

4. GYMNOSPERMS 700 living species conifers (such as pines and spruce)
cycads (such as the sago palm, Cycas revoluta)
ginkgos (the maidenhair tree, Ginkgo biloba)
gnetophytes (such as Mormon tea, Ephedra)

5. DIVISION GNETOPHYTA 70 species (3 genera) Welwitschia Ephedra Gnetum
two huge leathery leaves
Ephedra
Mormon tree
Gnetum
leaves angiosperm-like
vessels in the xylem
considered an angiosperm characteristic

6. DIVISION GNETOPHYTA have some angiosperm-like features
Cladistic analyses support placement of the gnetales (or some portion of them) as outgroups for the flowering plants

7. Welwitschia mirabilis

11. DIVISION CYCADOPHYTA pinnate leaves and circinate vernation
heterosporous
cones are unisexual
dioecious
free-swimming sperm

13. DIVISION GINKGOPHYTA Ginkgo biloba dioecious
the maidenhair tree
dioecious
males are more commonly planted
females produce seeds that have a nasty odor
pollination is by wind
swimming sperm

15. DIVISION CONIFEROPHYTA
Most common gymnosperms
Pines, spruces, firs, cedars, sequoias, redwood and yews
Can live more than 4000 y.o.

16. DIVISION CONIFEROPHYTA
evergreen
needle-like leaves
Needles have a thick cuticle
sunken stomates
reduced surface area

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