A plant is a living organism of the kind exemplified by trees, shrubs, herbs, grasses, ferns, and mosses, typically growing in a permanent site, absorbing water and inorganic substances through its roots, and synthesizing nutrients in its leaves by photosynthesis.
A plant needs sunlight, carbon dioxide, minerals and water to make food by photosynthesis. A green substance in plants called chlorophyll traps the energy from the Sun needed to make food. Chlorophyll is mostly found in leaves, inside plastids, which are inside the leaf cells. The leaf can be thought of as a food factory. Leaves of plants vary in shape and size, but they are always the plant organ best suited to capture solar energy. Once the food is made in the leaf, it is transported to the other parts of the plant such as stems and roots.
There are two types of photosynthetic processes: oxygenic photosynthesis and anoxygenic photosynthesis. The general principles of anoxygenic and oxygenic photosynthesis are very similar, but oxygenic photosynthesis is the most common and is seen in plants.
During oxygenic photosynthesis, light energy transfers electrons from water (H2O) to carbon dioxide (CO2), to produce carbohydrates. In this transfer, the CO2 is “reduced,” or receives electrons, and the water becomes “oxidized,” or loses electrons. Ultimately, oxygen is produced along with carbohydrates.
Plants also must get nutrients from the soil. Those nutrients get into the soil when decomposers break down waste and dead materials.
The roots of plants perform two main functions. First, they anchor the plant to the ground. Second, they absorb water and various nutrients dissolved in water from the soil.
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants. Flowers provide an eye-catching attribute to an otherwise plain, green-leaved plant. When insects, birds and some bats dip down to take a look at the flower and steal its nectar, they are inadvertently pollinating the plants by moving pollen from the male stamens to the female pistils. Flower is what (following pollination) produces the fruit. It is also where the seed is produced so that more of the same plant will grow in the future.
Mosses are small flowerless plants that typically form dense green clumps or mats, often in damp or shady locations. The individual plants are usually composed of simple leaves that are generally only one cell thick, attached to a stem that may be branched or unbranched and has only a limited role in conducting water and nutrients. They are typically 0.2–10 cm (0.1–3.9 in) tall, though some species are much larger. Dawsonia, the tallest moss in the world, can grow to 50 cm (20 in) in height.
A fern is a member of a group of vascular plants that reproduce via spores and have neither seeds nor flowers. Ferns are grown from spores. They are produced in specialized organs — the spore cases, or sporangia. Spores usualy look like small dots on the undersides of the fronds. Fern plants can drop millions of spores onto the ground, but only the few that find ideal conditions will grow. Ferns are some of the oldest plants in the world.
Grasses are arguably the most important plant species in existence. Grasses are technically known as Gramineae (or Poaceae but we will use the most well-known term Gramineae here) and are arguably the most important plant family in the world. Cultivated species of barley, corn, millet, oats, rice, rye and wheat are the staple foodstuff of many peoples around the world in both developed and developing countries.
Succulents are plants with fleshy, thick tissues adapted to water storage. The word “succulent” comes from the Latin word sucus, meaning juice, or sap. There are over 60 different succulent families and about 10,000 plant variants that differ in color, texture, and size.
A cactus is a succulent plant of the family Cactaceae. The word “cactus” derives, through Latin, from the Ancient Greek κάκτος, kaktos, a name originally used by Theophrastus (the successor to Aristotle) for a spiny plant whose identity is not certain. Most species of cactuses have lost true leaves, retaining only spines, which are highly modified leaves. Because cactuses have no leaves stems carry out photosynthesis.
Carnivorous plants are plants that derive some or most of their nutrients (but not energy, which they derive from photosynthesis) from trapping and consuming animals or protozoans, typically insects and other arthropods. Carnivorous plants have adapted to grow in places where the soil is thin or poor in nutrients, especially nitrogen, such as acidic bogs. Charles Darwin wrote Insectivorous Plants, the first well-known treatise on carnivorous plants, in 1875.
A tree is a perennial plant with a trunk, supporting branches and leaves in most species. They tend to be long-lived, some reaching several thousand years old. Trees have been in existence for 370 million years. It is estimated that there are just over 3 trillion mature trees in the world.
Plants play a vital role in the maintenance of life on Earth. All energy used by living organisms depends on the complex process of photosynthesis
They belong to the Plantae kingdom. Biologists estimate that there are about 320,000 species making up this kingdom.
Plants evolved from aquatic ancestors and have subsequently migrated over the entire surface of Earth, inhabiting tropical, Arctic, desert, and Alpine regions. Some plants have returned to an aquatic habitat in either fresh or salt water.
Plants range in size from diminutive duckweeds only a few millimetres in length to the giant sequoias of California that reach 90 metres (300 feet) or more in height.
The daily existence of human beings is directly influenced by plants. Plants furnish food; raw materials for industry, such as wood, resins, oils, and rubber; fibres for the manufacture of fabrics and cordage; medicines; and fuels.
The word “plant” can also mean the action of putting something in the ground. For example, farmers plant seeds in the field.
The scientific study of plants is known as botany, a branch of biology.