Without plants, nearly all life on Earth would end. Plants provide oxygen for humans and animals to breathe and they provide food for many animals. There are about 260,000 plant species in the world today. They are found on land, in oceans and in fresh water. They were the first living things on Earth.
Like animals, plants are living things, or organisms. These three features distinguish plants from animals:
- plants have chlorophyll, a green pigment necessary for photosynthesis
- their cell walls are made sturdy by a material called cellulose
- they are fixed in one place (they don?t move)
Plants are broadly divided into two groups: flower- and fruit-producing plants and those that do not produce flowers or fruits. Flowering and fruit plants include all garden flowers, agricultural crops, grasses, shrubs and most leaf trees. Non-flowering plants include pines, ferns, mosses and conifers (evergreen trees or shrubs that produce cones).
Some plants live in soil that doesn?t provide adequate nutrients, so they eat insects for nourishment. Insect-eating plants include pitcher plants and sundews.
Pitcher plants have trumpet-shaped leaves that contain a liquid. When the insect enters the leaf, tiny, stiff hairs prevent it from escaping. Juices secreted in the leaves help the plant to digest the insects.
Sundew plants have sticky hairs on their leaves that trap insects. The digestive juices in the leaves help the plant ?swallow? its victim.
Venus?s-flytrap has bristled leaves shaped like bear traps. When an insect touches the bristles, the ?trap? slams shut, trapping the insect.
Plant Hall of Fame
|Biggest Flower||Rafflesia arnoldii Each bloom is as big as 3 feet wide and can weigh up to 24 pounds. The reddish-brown flower, which emits a horrible odor, is found in Southeast Asia.|
|Oldest Trees||Bristlecone pines These trees are found in California, Nevada and Utah. Some in California?s White Mountains are more than 4,500 years old. The oldest-known living bristlecone pine more than 4,700 years old.|
|Biggest Fungus||Not only is the Armillaria ostoyae, or the honey mushroom, the largest fungus, it?s also probably the biggest living organism in the world. Located in Malheur National Forest in eastern Oregon, the fungus lives three feet underground and spans 3.5 miles.|
Fact Monster/Information Please Database, 2005 Pearson Education, Inc. All rights reserved.