PLANT CLASSIFICATION

We will be learning about and examining the different categories of plant life found on earth today. You have been living around and with these types of plants all of your life. Many of these plants can be found around your home or in your home. All animals depend on these plants for food and oxygen. We will see in our study of the different plant types, how they have evolved from very simple plants into the most complex types we have on earth.

Plants are different from animals because they can make their own food. The process is called photosynthesis and involves the plant's chlorophyll and sunlight. Plants are also different in that most are sessile, they do not move about like animals. There are two main groups of plants, non-vascular and vascular. Non-vascular plants lack true roots, stems and leaves. They must depend on osmosis and diffusion to move materials in and out of their structures. Due to the pull of gravity, these non-vascular plants do not grow tall. Vascular plants have advanced enough to develop true roots, stems and leaves. These plants have weed-developed tubes that will transport materials up and down their structures. Therefore, these plants can and do grow tall.

The simple plants that are non-vascular are algae, moss and liverworts. Sprirogyra (a type of algae) under a microscope Club mosses A leafy liverwort

Mosses and liverworts are also non-vascular plants. They have no true roots, stems or leaves so diffusion and osmosis move materials through these very "low to the ground" plants. They have structures that look like these plant parts but are not true vascular structures. Moss under a microscope

The first class of vascular plants involves plants known as ferns. These plants have true roots, leaves and stems. This situation allows ferns to grow tall because they can transport materials up and down the plants.

Ferns do not reproduce with seeds as do the higher plants but they reproduce with spores. These spores are located on the underside of fronds, the fern's leaf.

There are two groups of seed plants on earth, the gymnosperms and the angiosperms. Gymnosperms are the plants that are known as evergreens. They are also known as conifers.

The seeds of the gymnosperms are produced in a cone. The seeds are released from the cone when mature. This is why the seeds are referred to as "naked seeds". They are not protected once they are released from the cone. Some of the more common plants in this group are pines, cypress, firs and boxwoods. Cypress Pine cones

Snow covered douglas firs Boxwood

The most complicated plants on earth are the angiosperms. These are the flowering plants that produce seeds in a fruit. The angiosperms are deciduous because they lose their leaves each fall. Sunflower Flowering Cucumber The reproductive structure for angiosperms is the flower. Once the eggs inside the flower are fertilized the seeds develop. A fleshy fruit develops around the seeds to act as a protector for the seeds.

SUMMARY OF PLANT TAXONOMY Phylum 1. Clorophyta 2. Phaeophyta 3. Rhodophyta 4. Bryophyta 5. Tracheophyta Examples: Green Algae, Brown Algae, Red Algae Liverworts,Mosses, Ferns Gymnosperms, Angiosperms