Cascara Buckthorn facts for kids

Frangula purshiana is a plant known by many names, like cascara, cascara buckthorn, cascara sagrada, and bearberry. In the Chinook Jargon, it's called chittem stick or chitticum stick. This plant belongs to the Rhamnaceae family. It grows naturally in western North America, from southern British Columbia down to central California, and east to northwestern Montana.

For a long time, the dried bark of the cascara plant was used as a laxative (a medicine to help with constipation). Native peoples of the Pacific Northwest used it in their traditional medicine. Later, it was used worldwide in regular medicines until 2002.

What Cascara Looks Like

Cascara can be a large shrub or a small tree. It usually grows about 4.5 to 12 meters (15 to 40 feet) tall. Its trunk can be 20 to 50 centimeters (8 to 20 inches) wide. A special thing about this tree is that its buds don't have scales, which is unusual for plants in the northwest.

Bark and Leaves

The bark is thin and can be brownish or silver-gray. It often has light spots, sometimes from lichens growing on it. The inner bark is smooth and yellowish. It turns dark brown when it gets older or is exposed to sunlight. Cascara bark tastes very bitter. This strong taste can stay in your mouth for hours and even make your taste buds feel numb.

The leaves of the cascara tree are simple and fall off in autumn (they are deciduous). They grow in groups near the ends of the branches. Each leaf is oval-shaped, about 5 to 15 cm (2 to 6 inches) long and 2 to 5 cm (0.8 to 2 inches) wide. They are shiny and green on top, and a lighter, duller green underneath. The edges of the leaves have tiny teeth. They also have 10 to 12 pairs of veins that look like feathers. In the fall, the leaves turn yellow.

Flowers and Fruit

The flowers are very small, only about 3 to 5 millimeters (0.1 to 0.2 inches) across. They have five greenish-yellow petals that form a cup shape. These tiny flowers grow in clusters that look like umbrellas. They bloom for a short time in early to mid-spring and are gone by early summer.

The fruit is a small, round berry called a drupe. It's about 6 to 10 millimeters (0.2 to 0.4 inches) wide. At first, it's bright red, but it quickly turns deep purple or black when it ripens. Inside, the fruit has a yellow pulp and two or three hard, smooth seeds that are olive-green or black.

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  A close-up of a cascara leaf and its buds.

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  The splotchy bark of the cascara tree.

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  A branch showing its leaves, flowers, and buds.

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  Cascara leaves, a flower, and young fruits.

Where Cascara Grows

Cascara grows naturally from northern California up to British Columbia. It also grows east into the Rocky Mountains in Montana. You can often find it near streams in forests where both deciduous (leaf-shedding) and coniferous (cone-bearing) trees grow. It also likes moist mountain forests. Cascara often grows under bigger trees like bigleaf maple, red osier dogwood, and red alder.

Sadly, many cascara trees in the wild have been over-harvested. This means too much bark was collected because people wanted it so much. This has caused the number of cascara plants to drop in many areas.

Cascara in Nature

The fruit of the cascara plant is a food source for many animals. Birds, bears, raccoons, and other mammals eat the fruit. When they do, they help spread the seeds, which pass through their bodies without being digested.

Mule deer in Oregon and elk in northern Idaho eat the leaves, especially in winter. Olympic black bears, Oregon gray foxes, and raccoons also eat cascara leaves. In Northern California, ring-tailed cats eat them too.

Cascara trees can grow well even in shady places. When they grow together, they form thick areas that offer good hiding spots and warmth for wildlife.

If there's a fire, the top part of the cascara tree usually dies. But the plant can often grow back from its roots. After very big fires, new cascara plants can start growing from seeds that come from other areas, usually about two years later. Cascara often lives in places where fires happen every 30 to 150 years. It can also be found in areas where fires are much less common, happening only every 500 years or more.

Safety Concerns

The fruit and bark of cascara contain a bitter chemical. This makes them unsafe for humans to eat.

For many years, cascara was a main ingredient in over-the-counter (OTC) laxatives sold in pharmacies in North America. However, in 2002, the U.S. Food and Drug Administration (FDA) made a rule to ban cascara (and aloe) from being used in laxatives. This was because of serious safety concerns.

Using cascara can cause problems like dehydration (losing too much water from your body) and an imbalance of important chemicals in your body, like potassium and sodium. It can also cause irregular heartbeats and muscle weakness. There was also concern that it might cause cancer.

Laxatives like cascara should not be used by people with certain health conditions, such as Crohn's disease, irritable bowel syndrome, or kidney problems. It is also not safe for pregnant or breastfeeding women, or for children.

Dietary Supplements

In the United States, cascara is still sold as a dietary supplement. People sometimes take it by mouth to help with constipation. While it might be safe for a few days, there isn't enough scientific proof to be sure it's safe and works well for long-term use.

Using cascara can also affect how some prescribed drugs work. This includes medicines like digoxin, warfarin, corticosteroids, and diuretics.

Plant Chemicals

The bark of cascara contains many plant chemicals called quinoids. The chemicals that might cause a laxative effect are called hydroxyanthracene glycosides. These include cascarosides A, B, C, and D. About 8% of cascara's weight comes from these types of chemicals.

These chemicals are not easily absorbed in the small intestine. But they are changed by helpful bacteria in the large intestine. This change allows some of them to be absorbed in the colon. These chemicals may make the bowel contents larger by stopping the body from absorbing water and other chemicals. This increased volume can then trigger the muscles in the intestines to move, helping with constipation. Some of these chemicals might also leave the body through the kidneys. The extract from cascara bark also has a chemical called emodin, which may also help with its laxative effect.

How Cascara Was Used

Traditional Uses

The bark of the cascara plant, which was dried and used as a laxative.

In traditional medicine, cascara was used as a laxative. The dried, aged bark of Frangula purshiana was used by native cultures and later by European settlers. It was similar to other herbal laxatives made from plants like senna and rhubarb.

Commercially, it was called "cascara sagrada," which means 'sacred bark' in Spanish. In the traditional Chinook Jargon, it was known as "chittem bark" or "chitticum bark". After it was officially introduced to U.S. medicine in 1877, it became the preferred laxative over the berries of another plant, Rhamnus catharticus. As mentioned before, the high demand for cascara bark led to too much harvesting in the 1900s, which harmed the wild populations.

Preparing the Bark

The bark is usually collected in the spring or early summer. This is when it's easy to peel off the tree.

Once the bark is removed, it must be aged for several months. If you use fresh, dried bark, it can cause vomiting and severe diarrhea. The bark is usually dried in the shade to keep its yellow color. This aging process can be sped up by baking the bark at a low temperature for a few hours. Some suggestions for dosage were about 10 to 30 grains (0.6 to 2.0 cc) dissolved in water, or about 1 to 3 grams (0.035 to 0.1 ounces) of dried bark.

Other Uses

The fruit of the cascara plant can be eaten cooked or raw, but it also has a laxative effect. The food industry sometimes uses cascara as a flavoring in drinks like liquors and soft drinks, as well as in ice cream and baked goods. Honey made from cascara flowers tastes good, but it might also have a slight laxative effect.

Local people use the wood of the cascara tree for fence posts, firewood, and for turning on a lathe (making things like bowls). It is also planted as an ornamental tree (for its beauty). It provides food and a home for wildlife, and it can help stop soil erosion. Because of its bitter taste, cascara can even be used to help people stop biting their fingernails by putting it on their nails.

Images for kids

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  An illustration of Rhamnus purshiana (cascara).

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  A map showing the natural areas where cascara grows.

See also

In Spanish: Cáscara sagrada para niños