Nepedia
Back to Discover
Advanced Reader
🧬

Phaseolus vulgaris

life science Maturity 5-7 Next article →

The common bean, known scientifically as Phaseolus vulgaris, is a herbaceous annual plant. It is a vital member of the Fabaceae family, which is the legume family. These plants are incredibly important to global food systems. In 2022 alone, the world produced 28 million tonnes of dry common beans. India led this massive global production, accounting for 23% of the total amount.

Understanding how these plants grow involves looking at their unique biology. The plant produces green or purple leaves. Each leaf is divided into three smooth, oval leaflets. The flowers are small, measuring about one centimeter in length. They can appear in white, pink, or purple colors. Each flower contains 10 stamens. Because these flowers are self-pollinating, the plant can easily create stable cultivars.

Phaseolus vulgaris - Rattlesnake cultivar
Phaseolus vulgaris - Rattlesnake cultivar

After pollination, the plant develops seed pods. These pods are typically 1 to 1.5 centimeters wide. They can be many colors, including green, yellow, black, or purple. Each pod contains between 4 and 8 individual beans. The beans themselves are often kidney-shaped and up to 1.5 cm long. They can be smooth or mottled with two or more colors. Some varieties even grow a string along the pod.

Phaseolus vulgaris white beans, witte boon
Phaseolus vulgaris white beans, witte boon

There are two main growth styles for these plants. Bush varieties grow as erect, upright bushes. Pole varieties, also called running varieties, grow as long vines. All wild members of the species have a climbing habit. Cultivars are classified based on these different styles of growth.

Phaseolus vulgaris domestication
Phaseolus vulgaris domestication

History shows that humans have worked with these plants for millennia. Archaeologists found large-seeded varieties in the Peruvian highlands dating to 2300 BC. These seeds spread to coastal regions by 500 BC. In Mexico, small-seeded varieties appeared around 300 BC. These later spread north and east of the Mississippi River by 1000 AD. The species was domesticated in two distinct areas: Mesoamerica and the southern Andes. This created two separate genetic pools.

Anasazi beans (11002990623)
Anasazi beans (11002990623)

In the Americas, the common bean was part of the "Three Sisters." This was a system of growing beans, squash, and maize together. This method was central to indigenous American agriculture. The beans eventually reached Europe during the Columbian Exchange in the 16th century. Before this, Europeans grew different beans from Asia. Those Asian species were later moved to other genera like Vigna or Vicia.

Pinto bean
Pinto bean

There is a wide variety of specific bean types to explore. The Black Turtle bean is popular in Latin American cuisine. The Kidney bean is named for its resemblance to a human organ. The Anasazi bean is a dappled red and white variety. The Flageolet bean is picked before it is fully mature. Some beans, like the Calypso, are also known as panda beans.

Black Turtle Bean
Black Turtle Bean

Science also explains how these plants survive and how we must eat them. Most legumes acquire nitrogen through an association with rhizobia. These are nitrogen-fixing bacteria that help the plant. However, raw dry beans contain a toxic compound called phytohaemagglutinin. This protein can be dangerous if eaten uncooked. You can deactivate this toxin by boiling the beans for 30 minutes.

Phaseolus vulgaris white beans, witte boon
Phaseolus vulgaris white beans, witte boon

Finally, the genetics of the plant are quite interesting. The genome of Phaseolus vulgaris has 11 chromosomal pairs. This means the total number of chromosomes is 22. Its genome is one of the smallest in the legume family. It measures 625 Mbp per haploid genome. These beans are hardy and can maintain germination capacity for up to five years.

Painted Pony Bean
Painted Pony Bean
566 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (23)
File:Phaseolus vulgaris domestication.svg
Phaseolus vulgaris domestication.svg
File:Anasazi beans (11002990623).jpg
Anasazi beans (11002990623).jpg
File:Painted Pony Bean.JPG
Painted Pony Bean.JPG
File:Black Turtle Bean.jpg
Black Turtle Bean.jpg
File:Bolita Beans.jpg
Bolita Beans.jpg
File:Panda beans.jpg
Panda beans.jpg
File:Crimson cranberrybeans.jpg
Crimson cranberrybeans.jpg
File:Beans in Ventimiglia.jpg
Beans in Ventimiglia.jpg
File:Canned flageolets.jpg
Canned flageolets.jpg
File:Red Rajma BNC.jpg
Red Rajma BNC.jpg
File:Jacob's Cattle beans with pods.jpg
Jacob's Cattle beans with pods.jpg
File:Mocha with Cherry.jpg
Mocha with Cherry.jpg

+ 11 more

More to explore

✨ What else?

Related topics you might enjoy

🔬 Go deeper

More advanced topics to explore

🪜 Step back

Simpler topics to build understanding

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.