Cactus come in many different shapes and sizes and can be found all over the world in hot, dry climates. There are about 2,000 different kinds of cactuses. The cactus plant does not have leaves (although some indoor cactus plants seem to have leaves) and have only thick, fleshy stems and spines. Cactus stems hold and store water. In fact, they are very efficient at water management and have a very well organized way to collect rain water—the roots spread wide and shallow and can soak up rain water. They also gather water from the air—with water droplets from the fog. The water is absorbed into a “guey tissue called mucilage.” (Angier, 2017). The cactus also conserves water through multi-step photosynthesis process. “Most plants photosynthesize in the daytime, opening pores in their leaves to allow carbon dioxide gas to diffuse in and then using the ambient solar energy to stitch the harvested carbon and water into sugary fuel.” (Krehel, 2015). But the cactus waits until dark to absorb carbon dioxide and keeps the gas inside until the next morning to convert it to sugar while its apertures stay closed.
Scientists have found that “as many as 100 species of cactuses are essentially breasts for ants, exuding through tiny nipples in their flesh a minute but irresistible supply of sweet nectar.” (Angier). Many cactuses grow slowly and can live anywhere from 50 to 200 years. Cactuses are useful: humans eat cactus and its fruit, birds and animals life and hide in cactus, and insects feed on the cactus.
The cactus often grow in rows or patterns which may be related to how they reproduce. Some cactuses stems break off and fall to the ground. They later grow into the soil and start a new plant. Flowers, fruit, and seeds also help the cactus multiply.
Below are a few varieties of cactus:
- Prickly pears: look like pancakes because they have many flat pads. The fruit of the prickly pear are juicy and some people eat them as a vegetable
- Barrel shaped cactus: a common variety of cactus with ribs and firm spines. The plant produces juicy fruit, but they don’t taste good
- Chollas: stems of the jumping cholla fall to the ground; desert packrats make theirs dens with cholla.
- Fish hook cactus: a large category of around 150 species, are typically small cacti of about 6-7 inches tall and grow on the US Mexico border. Its surface covered with long, curved barbs and a snarl of fibrous hairs.
Angier, Natalie. “As Rains Ease in the West, Cactuses Shine Brighter Than Ever.” New York Times (New York, NY), April 24, 2017. Accessed August 10, 2017. https://www.nytimes.com/2017/04/24/science/cactus-superbloom-spring.html?_r=0.
Dotschkal, Janna. “Cactus Flowers: Mother Nature’s Fireworks.” National Geographic. Last modified July 3, 2015. Accessed August 10, 2017. http://proof.nationalgeographic.com/2015/07/03/cactus-flowers-mother-natures-fireworks/.
Mauseth, James D. “Tiny but Complex Foliage Leaves Occur in Many “Leafless” Cacti (Cactaceae).” International Journal of Plant Sciences 168, no. 6 (January 2007): 845-53. Accessed August 10, 2017. http://www.journals.uchicago.edu/doi/abs/10.1086/518273.