20.2 Classification of Plants - Clinton Public School District

20.2 Classification of Plants

Bell Ringer

• Find your lab from yesterday• Get your lab log book and complete it for

yesterday’s lab.

20.2 Classification of Plants

KEY CONCEPTPlants can be classified into nine phyla.

20.2 Classification of Plants

Mosses and their relatives are seedless nonvascular plants.

• Nonvascular plants grow close to the ground to absorb water and nutrients.

• Seedless plants rely on free-standing water for reproduction.

• Liverworts belong to phylum Hepatophyta. – often grow on wet rocks or

in greenhouses– can be thallose (looks like

lobes of a liver flat on the ground) or leafy

20.2 Classification of Plants

• Hornworts belong to phylum Anthocerophyta. – found in tropical forests and along streams

– flat, lobed body with little green “horns”

20.2 Classification of Plants

• Mosses belong to phylum Bryophyta.

20.2 Classification of Plants

– most common seedless nonvascular plants– sphagnum moss commonly used by humans as “peat”

–Peat does not decay when it dies, has antibacterial properties, and was formerly used as diapers and bandages.

-Do not have true leaves

-Very tolerant of harsh weather and low nutrient soil

-One of the 1st plants to colonize bare land and begin soil making process in the early stages of primary succession.

20.2 Classification of Plants

Question

• Why can’t nonvascular plant grow tall???

20.2 Classification of Plants

Club mosses and ferns are seedless vascular plants.• A vascular system allows club mosses and ferns to grow

higher off the ground.• Both need free-standing water for reproduction. • Approximately 300 mya shallow swamps were home to

enormous seedless vascular plants. Overtime the dead remains of these plants were pressed and heated underground where they turned into coal. This is why they call coal fossil fuel.

• Club mosses and ferns are seedless vascular plants. They still depend on water for reproduction.

20.2 Classification of Plants

• Club mosses belong to phylum Lycophyta. -not true mosses -oldest living group of vascular plants

20.2 Classification of Plants

• Ferns and their relatives belong to phylum Pterophyta.

frond

fiddlehead

– whisk ferns and horsetails are close relatives of ferns– ferns have large leaves called fronds– Newly forming fronds uncurl as they grow and are called

fiddleheads

20.2 Classification of Plants

• Whisk ferns grow mostly in tropics and subtropics

• Lack true roots and leaves• Horsetails grow in wetland

areas along rivers and streams.

20.2 Classification of Plants

Question

• Why do most seedless vascular plants live in moist areas?

20.2 Classification of Plants

Bell Ringer Pg. 622 #1 and #2

Then look over terms for vocabulary quiz!

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

20.2 Classification of Plants

– Seeds allow plants to disperse to new places- Ex: wind, water, or animals carry seeds far from the

individual plant. (maples seed’s “wings”)– Seeds cans survive for many months, even years, in

a dormant state and can withstand harsh conditions that would kill and adult plant.

– Plants can be grouped according to whether their seeds are enclosed in fruit.

20.2 Classification of Plants

• Gymnosperms do not have seeds enclosed in fruit. – most gymnosperms are cone-bearing and evergreen.– the cone is reproductive structure of most

gymnosperms.– 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 in phylum Cycadophyta.

– look like palm trees with large cones

– grow in tropical areas– Many species are

endangered because of their slow growth and loss of habitat in these tropical areas.

20.2 Classification of Plants

• Ginkgos are gymnosperms in phylum Ginkgophyta.– only one species alive today, Ginkgo biloba– grown in gardens and used in urban landscaping – Native to China – It may be the oldest living species of seed plants.

20.2 Classification of Plants

• Conifers are gymnosperms in phylum Coniferophyta.– most common

gymnosperms alive today

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

– Needle like leaves

20.2 Classification of Plants

• Angiosperms have seeds enclosed in some type of fruit. – A flower is the reproductive structure of angiosperms.– A fruit is a mature ovary of a flower.

• Angiosperms, or flowering plants, belong in phylum Anthophyta.

-Fruits vary from a juicy peach to the fluff surrounding dandelion seeds

20.2 Classification of Plants

Common misconception

• Our culture tends to divide produce into fruits and vegetables, yet the distinction between the two is often artificial, based on taste or appearance more than on botanical classification. For example you may think of a tomatoes as a vegetable and grapes as a fruit when in fact they are both fruits.

• In botany a fruit is simply the ripened ovary of any flowering plant. This means that peppers, tomatoes, squash, green beans, eggplant, watermelon, apples, bananas, cherries, peaches, cucumbers are all fruits. Even though in cuisine we refer to some as vegetables.

• Vegetable really refers to the edible leaves, stalks, flower buds, or roots of a plant.

20.2 Classification of Plants

Question

• What adaptation of seed plants allows sperm to reach and fertilize an egg in the absence of water??

20.2 Classification of Plants

Question

• What are the 9 phlya covered in section 2?