Gymnosperms- Chapter 18
Naked versus Enclosed Seed Plants Gymnosperms Gymno- gr. naked. Sperma- gr. seed. Angiosperms Angeion- gr. vessel.
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 Zamia 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