Upload
buiphuc
View
225
Download
3
Embed Size (px)
Citation preview
Gymnosperms- Chapter 18
Naked versus Enclosed Seed Plants
• Gymnosperms
– Gymno- gr. naked.
– Sperma- gr. seed.
• Angiosperms
– Angeion- gr. vessel.
– Sperma- gr. seed.
Extant Gymnosperms
• Match the common name on the right to the
phylum on the left.
– 1) Cycadophyta a. ginkgo
– 2) Ginkgophyta b. conifers
– 3) Coniferophyta c. cycads
– 4) Gnetophyta d. gnetophytes
Cycadophyta
• Cycas- gr. palm.
• Tracheids, but no vessel elements.
• Sperm present, multiflagellated.
• Palmlike leaves.
• Pollen tube does not fuse with the egg cell.
• Ovulate (megasporangiate) & microsporangiate cones simple & on separate plants.
• 11 genera & 140 species.
• Examples- Cycas & Zamia.
Zamia
Cycas
Ginkgophyta
• Yin- ch. silver, hing- ch. apricot.
• Tracheids, but no vessel elements.
• Sperm present, multiflagellated.
• Fan-shaped leaves.
• Pollen tube does not fuse with the egg cell.
• Ovulate & microsporangiate cones on separate plants; fleshy-coated seeds.
• 1 genus & 1 species.
• Examples- Gingko biloba= maidenhair tree.
Coniferophyta
• Con- gr. cone, fer- L. bear.
• Tracheids, but no vessel elements.
• Sperm not motile.
• Needlelike or scalelike leaves.
• Pollen tube fuses with egg cell.
• Ovulate & microsporangiate cones on same plant; ovulate cones compound.
• 70 genera & 630 species.
• Examples- Pinus, Picea, Juniperus, Abies, Cupressus.
True or False. These winglike structures are
female pollen grains.-------------------------->
Pinus- pine (Pinaceae).
Metasequoia- Dawn redwood.
Wollemia nobilis- Wollemi pine.
Gnetophyta
• Gneto- Malay gnenom.
• Tracheids and vessel elements.
• Sperm not motile.
• Scalelike, leaflike, broad and leathery leaves.
• Pollen tube fuses with egg cell.
• Ovulate & microsporangiate cones compound & mostly borne on separate plants.
• 3 genera & 70 species.
• Examples- Gnetum, Ephedra, Welwitschia.
Gnetum
Ephedra
Welwitschia