20.2 Classification of Plants

Vascular Cone-bearing Plants

Conifers

20.2 Classification of Plants

Seed plants include cone-bearing plants and flowering plants.

• Seed plants have several advantages over their seedless ancestors. – can reproduce without free-standing water, via pollination

– pollination occurs when pollen meets female plantparts

– seeds nourish and protect plant embryo

– seeds allow plants to disperse to new places

20.2 Classification of Plants

• Gymnosperms do not have seeds enclosed in fruit. – “Gymnosperm” comes from a Greek word meaning

“naked seed”– most gymnosperms are cone-bearing and evergreen.– pollen is produced

in male cones.– eggs are produced

in female cones.

– seeds develop on scales of female cones.

20.2 Classification of Plants

• Cycads are gymnosperms

– look like palm trees with large cones– grow in tropical areas

20.2 Classification of Plants

• Ginkgos are gymnosperms– only one species alive today, Ginkgo biloba– grown in gardens and used in urban landscaping

20.2 Classification of Plants

• Conifers are gymnosperms in phylum Coniferophyta.– most common

gymnosperms alive today

– includes pines, spruce, cedar, fir, and juniper

20.2 Classification of Plants

20.2 Classification of Plants

Life Cycle of a Conifer