What to know about Rheum officinale (rhubarb) before using it medicinally

Rheum officinale, commonly known as rhubarb, is a medicinal herb that has been used for centuries to treat various health conditions, including digestive issues, inflammation, and skin problems, due to its high content of anthraquinones, which have been shown to have potent anti-inflammatory and laxative properties.

This hardy perennial herb requires well-drained soil and partial shade, and can be grown in USDA zones 3-8, making it a versatile and relatively easy addition to home gardens. Botanically speaking, Rheum officinale belongs to the Polygonaceae family and is characterized by its large, fleshy, and tart stalks, as well as its distinctive green leaves.

Historical records of Rheum officinale date back to ancient China, where it was first cultivated and used as a medicinal herb by Chinese physicians as far back as the 16th century.

This article explains the medicinal, horticultural, botanical, and historical aspects of Rheum officinale.

What are the medicinal properties of Rheum officinale?

Rheum officinale helps with digestive issues, such as constipation and diarrhea, due to its purgative and laxative properties. It has been used to treat various gastrointestinal disorders, including inflammatory bowel disease and irritable bowel syndrome.

The active constituents of Rheum officinale include anthraquinones, such as emodin, aloe-emodin, and chrysophanol, which contribute to its medicinal properties. These compounds are responsible for its laxative and purgative effects. They also possess anti-inflammatory and antimicrobial activities.

The parts of the plant most used for medicinal purposes are the root and the rhizome. These contain the highest concentration of anthraquinones and other bioactive compounds. The root and rhizome are traditionally processed and dried to produce rhubarb powder or tablets.

Improper use of Rheum officinale can lead to side effects such as abdominal cramps, diarrhea, and electrolyte imbalances. Long-term or excessive use can cause dependence, leading to withdrawal symptoms. Additionally, the plant can interact with certain medications, such as blood thinners.

The most common precautions to take when using Rheum officinale medicinally include consulting a healthcare professional, especially for pregnant or breastfeeding women. A thorough medical evaluation and monitoring of electrolyte levels and kidney function are also recommended.

What are the horticulural aspects of Rheum officinale?

Rheum officinale grow best in cooler climates with well-drained soil and full sun. It requires a pH between 6.5 and 7.5 and can tolerate a wide range of temperatures from 35°F to 70°F (2°C to 21°C). Soil with a high organic matter content promotes healthy growth.

For planting, choose a location with full sun and well-drained soil. Rhubarb plants should be spaced 2-3 feet apart and 12-18 inches deep. Dig a hole 12-18 inches deep, add a 2-inch layer of compost, and mix well. Plant the crown (base of the plant) 2-3 inches deep, water thoroughly, and mulch around the base.

Harvest rhubarb when the stalks reach 10-12 inches in length, usually in late spring. Cut the stalks at the base, leaving 2-3 inches of stem attached. Harvest in the morning, when the plants are at their highest water content, to avoid stress on the plant. Continue harvesting for 2-3 weeks, then allow the plant to rest.

Common pests affecting rhubarb include the Japanese beetle and the rhubarb curculio. Rhubarb crown rot and root rot are common diseases caused by fungal pathogens such as Pythium and Phytophthora. Regularly inspect the plant for signs of pests or disease, and take action promptly if necessary to prevent spread.

What are the botanical aspects of Rheum officinale?

Rheum officinale is a perennial plant belonging to the family Polygonaceae. Its leaves are large, ovate, and alternate, measuring 30-60 cm in length, with a distinctive petiole and a prominent midrib. The plant's stem is erect, branched, and attains a height of 1.5-2.5 meters.

Rheum officinale is a member of the genus Rheum, which comprises about 60 species, all of which are native to Asia. It is classified within the family Polygonaceae, which comprises about 2,000 species, including buckwheat, rhubarb, and smartweed. The plant's species name, officinale, indicates its traditional use as a medicinal herb.

There are several variants of Rheum officinale, including Rheum officinale var. sibbaldianum and Rheum officinale var. sinense. These variants exhibit slight differences in leaf shape, size, and color. Rheum officinale var. sibbaldianum is commonly found in the mountainous regions of China, while Rheum officinale var. sinense is widely distributed in East Asia.

Rheum officinale is native to the mountainous regions of China, specifically in the provinces of Qinghai, Gansu, and Sichuan. It has also been naturalized in the mountainous regions of Eastern Europe, the Caucasus, and Japan. The plant thrives in areas with cold winters and cool summers, at elevations ranging from 1,000 to 3,000 meters above sea level.

The life cycle of Rheum officinale begins with seed germination in spring, when the plant produces new leaves and stems. The plant grows rapidly during the summer months, producing large leaves and a robust stem. In the fall, the plant dies back, leaving the roots and crowns intact. The plant's underground parts remain dormant during the winter months and begin to grow again in the spring.

What are the historical aspects of Rheum officinale?

Rheum officinale is a perennial plant native to Asia. Historically, its edible stems were used as a vegetable, while its roots were used for medicinal and culinary purposes. In ancient China, it was valued for its laxative properties. Rhubarb was also consumed by the ancient Greeks and Romans. Its use as a purgative was mentioned in the writings of Hippocrates.

In Greek mythology, the plant was associated with the goddess of the underworld, Persephone. According to legend, she discovered the plant's medicinal properties and introduced it to the world above. The Greeks also linked rhubarb to the goddess of fertility, Demeter. In some cultures, the plant was believed to have purifying powers. Rhubarb was also associated with the cycles of nature.

In many cultures, rhubarb has symbolic meanings. In the Victorian era, it was a symbol of disdain and contempt. In contrast, in ancient China, it was considered a symbol of good fortune and prosperity. In the language of flowers, rhubarb was used as a symbol of bitter regret. The plant's reddish stalks were also associated with the color of love and passion. In some cultures, the plant was seen as a representation of the cycle of life.

Historical texts provide evidence of the use of rhubarb for medicinal and culinary purposes. The Chinese medical text, Shen Nong Ben Cao Jing, described the plant's laxative properties. The Greek physician, Dioscorides, mentioned its use as a purgative. The Roman naturalist, Pliny the Elder, also described the plant's medicinal properties. In the Middle Ages, the Arab physician, Ibn Sina, wrote about the plant's use as a treatment for fever and rheumatism.

Archaeological findings have revealed evidence of the use of rhubarb in ancient times. In the ancient Chinese city of Lanzhou, archaeologists discovered a 2,000-year-old rhubarb recipe. In the tomb of the Egyptian pharaoh, Tutankhamun, archaeologists found rhubarb seeds and roots. In the Roman ruins of Pompeii, archaeologists discovered a kitchen garden containing rhubarb plants. These findings confirm the plant's long history of use and trade.