Plant Classes and Life Cycles

Plant Science

Classification of Plants

Four Major Groups

1. gymnosperms

2. angiosperms

3. mosses

4. ferns

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Gymnosperms

• plants that produce seeds not protected by fruit

• means "naked seed" in Greek• examples:

– pines, firs, spruces– redwood– ginkgo

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Angiosperms

• plants that flower and produce seeds protected by fruit or pods

• means "covered seed" or "enclosed seed" in Greek

• made up of two classes: – monocotyledons (a.k.a. "monocots")

– dicotyledons (a.k.a. "dicots")4www.OneLessThing.net

Characteristics of Moncots

• seeds have one cotyledon

• seedlings have one seed leaf

• vascular bundles are scattered

• leaves have parallel veins

• flower parts are in multiples of 3

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Characteristics of Dicots

• seeds have two cotyledons

• seedlings have two seed leaves

• vascular bundles are arranged in a circle

• leaves have netted veins

• flower parts are in multiples of 4 or 5

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Plant Taxonomy

• Scientific naming system used today is called binomial nomenclature

• developed by Linnaeus; names are in Latin and written in italics

• the first name is the genus

• the second name is the species

• species can be further subdivided into varieties

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Life Cycles of Plants

Three Major Groups

1. annuals

2. biennials

3. perennials

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Annuals

• plants that complete their life cycle in one year• examples:

– tomatoes– marigolds– pansies

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Biennials

• plants that complete their life cycle in two growing seasons

• examples:– hollyhock– parsley

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Perennials

• plants that produce for more than two years• divided into two classes:

– herbaceous– woody

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Two Classes of Perennials

• herbaceous: plants that have soft stems that are killed by frost

• perennials: have stems and buds that can survive winter frost (trees for example)

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Thank youfor learning with us!

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