Phylum Gymnospermae The Gymnosperms, or Plants with Cones - PowerPoint PPT Presentation

Phylum Gymnospermae The Gymnosperms, or Plants with Cones

Gymnosperms  Have seeds, but not covered by fruit  All are perennials – trees or shrubs  Have windborne pollen (male gamete)

Gymnosperms  Three major types:  Cycads  Ginkgos  Conifers (most common type)

Cycads  Ancient group  Today, found only in tropics (warmer climate required)  Resemble very short palms, but have tough, leathery leaves  Central area produces seeds

Cycads

Cycads – locations in world

Cycads  Tropical plants

Cycads  Plants are dioecious ( separate male and female plants)  Diagram of  Male cones

Cycads  Cones are in central area

Gingkos  Trees, dioecious, endemic to China  Often used in urban areas, tolerant to smog

Gingkos  Have characteristic, fan-shaped leaves, with vertical slit in centre, and parallel veins

Gingkos  Only one species remaining from this group, called Gingko biloba

Gingkos  Tree – with very separate branch appearance (not bushy)

Gingkos

Conifers  Produce seeds in cones  Most important source of wood  Found in temperate to tropic regions

Conifers  Forests:  Boreal /Taiga of northern Canada

Conifers

Conifers  Small leaves – needles or scales

Conifers  No flowers, gamete produced in cones  Male cone Female cone

Conifers  Female cones are often woody and long- lasting

Conifers  Can withstand cold, snow (boreal forests of northern Canada, Eurasia)

Conifers  Also grow in the tropics – eg. the Caribbean! Pinus caribea

Gymnosperms - summary  Old plant group  Better adapted to life on land than mosses or ferns  Windborne pollen (contains male gamete)  Have seeds (not enclosed in fruit)  Have no flowers