Gymnosperms- Chapter 18

Naked versus Enclosed Seed PlantsGymnospermsGymno- gr. naked.Sperma- gr. seed.AngiospermsAngeion- gr. vessel.Sperma- gr. seed.

Extant GymnospermsMatch the common name on the right to the phylum on the left.1) Cycadophyta a. ginkgo2) Ginkgophytab. conifers3) Coniferophyta c. cycads4) Gnetophyta d. gnetophytes

CycadophytaCycas- 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

GinkgophytaYin- 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.

ConiferophytaCon- 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 arefemale pollen grains.-------------------------->

Pinus- pine (Pinaceae).

Metasequoia- Dawn redwood.

Wollemia nobilis- Wollemi pine.

GnetophytaGneto- 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