Gossypium

Cotton plants grow soft stuff.

We use it for clothes. It comes from a small pod. Each seed in the pod has soft hair. This hair is a natural fiber.

People use this hair to make thread. They use the thread to weave cloth. The plants can be white or brown. Some can even be green! These plants grow in warm lands. They are very important to the world.

Cotton comes from plants in the genus Gossypium.

These plants live in warm, tropical areas. Some grow as small shrubs. Others can grow as tall trees.

Cotton is very important to our world. It is the main natural fiber we use. Most of the world's natural fiber is cotton. We also use the seeds for oil and animal food.

Inside the plant, seeds grow in a pod called a boll. Each seed has soft hair around it. To get the fiber, we use a way called ginning. This set of steps separates the hair from the seed.

First, we take the long hairs. We call these staples. People twist them into yarn to make fine cloth. Next, we take the short hairs. These are called linters. They are used to make lower quality cloth.

Cotton can be many colors. It can be white, brown, or even green. Scientists study these plants to make them better. They want plants that can survive bugs or dry weather.

The plants in the genus Gossypium are very special to people. They are the source of cotton, which is a natural fiber. In fact, cotton makes up about 80% of all natural fiber used today. These plants grow in warm, tropical, and subtropical areas. You can find them in parts of Africa, Asia, and South America. They are important for farming and trade in these regions.

How do we get the cotton we use? It starts inside a part of the plant called a boll. The seeds are kept inside this small capsule. Each seed is covered in two types of fibers. To separate them, people use a process called ginning. First, they remove the long fibers, which are called staples. These are twisted into yarn for high quality cloth.

Scientists have studied these plants for a long time. The genus likely began about 5 to 10 million years ago. Most wild plants are diploid, which means they have two sets of chromosomes. However, five species from America and the Pacific are tetraploid. This means they have four sets of chromosomes. This happened during a single hybridization event about 1.5 to 2 million years ago.

There are about 50 different species in this group. One species, G. hirsutum, makes up 97% of the world's cotton. Another species, G. barbadense, makes up about 1% to 2%. Other types like G. arboreum and G. herbaceum make up about 1% together. Cotton can even grow in different colors like white, brown, or green. Some species grow as small shrubs, while others grow as trees.

We can see how these plants connect to our daily lives. The fibers make the clothes we wear every day. We also use the seeds for oil and animal feed. Scientists are even working to make the plants better. They try to breed new varieties that can survive bugs or dry weather. This helps farmers grow more food and fiber for the world.

The genus *Gossypium* includes flowering plants that provide us with cotton. These plants belong to the mallow family, known as Malvaceae. Cotton is the most important natural fiber used by humans today. It accounts for approximately 80% of all natural fiber production worldwide. Because cotton is so vital for industry and trade, scientists study it closely. The name *Gossypium* comes from the Arabic word "goz," which means a soft substance.

These plants grow in many different ways depending on where they live. They are usually shrubs or shrub-like plants. However, they can be very diverse in their shapes and how they adapt to nature. In Australia, some species are herbaceous perennials that have adapted to survive fires. In Mexico, some species actually grow as trees. Most of these plants live in the warm, tropical, and subtropical regions of the Old and New Worlds. They often thrive in areas that are arid or semiarid.

To understand how we get cotton, we must look at the plant's structure. The seeds are held inside a protective capsule called a boll. Every single seed inside the boll is surrounded by two different types of fibers. Humans use a process called ginning to separate these fibers from the seeds. During the first ginning, workers remove the longer fibers known as staples. These staples are twisted together to create yarn for high-quality textiles. The second ginning removes the shorter fibers, which are called linters. These linters are used to weave lower-quality textiles.

Scientists study the genetics of these plants to understand their history. The *Gossypium* genus likely began about 5 to 10 million years ago. Most wild cotton species are diploid, meaning they have two sets of chromosomes. However, five specific species from the Americas and Pacific islands are tetraploid. A tetraploid plant has four sets of chromosomes. This happened because of a single hybridization event roughly 1.5 to 2 million years ago. The tetraploid species include *G. hirsutum*, *G. tomentosum*, *G. mustelinum*, *G. barbadense*, and *G. darwinii*.

There are about 50 different species in this genus, and new ones are still being found. Not all cotton is the same, and different species serve different roles. *G. hirsutum* is the most important, making up 97% of the world's cotton production. *G. barbadense* provides about 1% to 2% of the world's supply. The species *G. arboreum* and *G. herbaceum* together make up about 1%. Cotton fibers can even grow in natural colors like white, brown, or green. Some varieties are even mixed with these colors.

Researchers are working hard to map the cotton genome through sequencing. A large public project began in 2007 to sequence the genome of cultivated cotton. This cotton is "allotetraploid," which means it contains two distinct subgenomes. These are called the At and Dt subgenomes. To solve this puzzle, scientists first sequence the D-genome relative, *G. raimondii*. This wild South American species is easier to sequence because its genome is smaller. It has nearly one-third the number of bases found in tetraploid cotton. Once the A and D genomes are understood, scientists can better map the complex cultivated varieties.

Growing cotton is not always easy because of many natural challenges. Plants must face various pests, such as the boll weevil and the cotton aphid. Other insects like the cotton bollworm and spider mites can also damage the crops. Diseases caused by fungi and bacteria are also a major concern for farmers. These include issues like anthracnose boll rot and black root rot. To help, scientists use selective breeding and hybridization. They try to cross-breed wild species with commercial ones to create plants that resist insects and survive droughts. This helps ensure cotton remains a steady resource for the world.