''Rheum palmatum'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

in the knotweed

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Polygonaceae. It is commonly called Chinese rhubarb, ornamental rhubarb, Turkey rhubarb or East Indian rhubarb. ''Rheum palmatum'' is a

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of t ...

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

related to the edible

rhubarb Rhubarb is the fleshy, edible stalks ( petioles) of species and hybrids (culinary rhubarb) of ''Rheum'' in the family Polygonaceae, which are cooked and used for food. The whole plant – a herbaceous perennial growing from short, thick rhizo ...

. It is primarily used in traditional medicine, and as an ornamental subject in the garden.

Taxonomy

Agnia Losina-Losinskaja Agnia Sergeyevna Losina-Losinskaja () (1903–1958) was a Soviet botanist. Her family name is also transcribed as Lozina-Lozinscaia, and Lozina-Lozinskaja. She is the author or co-author of the botanical names of at least 216 taxa, including spe ...

proposed classifying it in the

section Section, Sectioning or Sectioned may refer to: Arts, entertainment and media * Section (music), a complete, but not independent, musical idea * Section (typography), a subdivision, especially of a chapter, in books and documents ** Section sign ...

''Palmata'' in the ''Flora SSSR'' in 1936. In the 1998 ''Flora Republicae popularis Sinicae'' A. R. Li maintains this classification for this species.

Description

Its lobed leaves are large, jagged and hand-shaped, growing in width to two feet. Chinese rhubarb has thick, deep roots.

Similar species

The species ''

Rheum tanguticum Rheum (; from Greek: ῥεῦμα ''rheuma'' 'a flowing, rheum') is a thin mucus naturally discharged from the eyes, nose, or mouth, often during sleep (cf. mucopurulent discharge).Amodio, Aime"Where Do Eye Boogers Come From?" Families.com bl ...

'' is closely related to ''R. palmatum''. ''R. palmatum'' can be distinguished from ''R.'' × ''hybridum'', the garden rhubarb we eat, by size; while garden rhubarb only grows to a few feet in height, Chinese rhubarb can grow to six feet.

Karyotypy

''R. palmatum'' has a

chromosome A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ...

count of 2''n''=22.

Distribution

It is native in the regions of

western China Western China (, or rarely ) is the west of China. In the definition of the Chinese government, Western China covers one municipality (Chongqing), six provinces (Sichuan Sichuan (; zh, c=, labels=no, ; zh, p=Sìchuān; alternatively r ...

, northern

Tibet Tibet (; ''Böd''; ) is a region in East Asia, covering much of the Tibetan Plateau and spanning about . It is the traditional homeland of the Tibetan people. Also resident on the plateau are some other ethnic groups such as Monpa people, ...

, and the

Mongolian Plateau The Mongolian Plateau is the part of the Central Asian Plateau lying between 37°46′-53°08′N and 87°40′-122°15′E and having an area of approximately . It is bounded by the Greater Hinggan Mountains in the east, the Yin Mountains to th ...

Folk medicine

'', '' R. rhabarbarum'' and '' R. officinale'' and a few others, are all harvested for their roots, which are used as a herbal medicine. This became one of the most prominent items traded along the

Silk Road The Silk Road () was a network of Eurasian trade routes active from the second century BCE until the mid-15th century. Spanning over 6,400 kilometers (4,000 miles), it played a central role in facilitating economic, cultural, political, and reli ...

. Imported roots of various rhubarb species were widely used in Europe for hundreds of years before the identity of the plant was eventually discovered. Some of the common names associated with ''Rheum palmatum''"Russian rhubarb", "Turkey rhubarb", and "Indian rhubarb"are directly affiliated with the trade routes for rhubarb from China. The root is known for its purported purging effects and suppressing fever. In ancient China, rhubarb root was taken to try to cure stomach ailments and as a "cathartic" (an agent used to relieve constipation), and used as a

poultice A poultice, also called a cataplasm, is a soft moist mass, often heated and medicated, that is spread on cloth and placed over the skin to treat an aching, inflamed, or painful part of the body. It can be used on wounds, such as cuts. 'Poultice' ...

for "fevers and edema" (swelling caused by fluid retention in the body tissues). It was given its Latin name by

Carolus Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his Nobility#Ennoblement, ennoblement in 1761 as Carl von Linné#Blunt, Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalise ...

in the year 1759 and first grown in Britain around 1762. The first International Symposium on Rhubarb was held in China in 1990. Its objective was to verify the scientific data and treatment of Chinese Rhubarb used by Chinese

pharmacopoeia A pharmacopoeia, pharmacopeia, or pharmacopoea (from the obsolete typography ''pharmacopœia'', meaning "drug-making"), in its modern technical sense, is a book containing directions for the identification of compound medicines, and published by ...

Health risks

Pregnant women should avoid all intake of the plant since it may cause uterine stimulation. If taken for an extended amount of time, adverse effects include: "hypertrophy of the liver, thyroid, and stomach, as well as nausea, griping, abdominal pain, vomiting, and diarrhea." Though the root of the Chinese rhubarb is a key facet of herbal medicine, its leaves can actually be poisonous if consumed in large amounts due to the

oxalic acid Oxalic acid is an organic acid with the systematic name ethanedioic acid and formula . It is the simplest dicarboxylic acid. It is a white crystalline solid that forms a colorless solution in water. Its name comes from the fact that early inve ...

content. Patients with "arthritis, kidney problems, inflammatory bowel disease, or intestinal obstruction" should refrain from consumption.

Cultivation

Ornamental use

With its large palmate leaves and tall panicles of pink flowers, ''Rheum palmatum'' is a bold statement plant for the temperate garden, that grows up to tall and broad. It is hardy down to . It is propagated by seed in the spring, or by root division in spring or autumn. It grows best in full sunlight in well-drained soil. The following cultivars have gained the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr (Nort ...

’s

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established annual award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. History The Award of Garden Merit ...

:- * ’Ace of Hearts’ – compact cultivar to * ’Bowles’s Crimson’ * ’Hadspen Crimson’

Farming as medicinal herb

Since it is the roots and

rhizome In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

which serve as this plant's source of medicinal usage, special care is taken in their preparation. When 6–10 years old, the rhizomes of these plants are removed from the ground in the autumn when both its stems and leaves changed to yellow wild. Furthermore, the removal of the lateral rootlets and the crown are removed, leaving only the root. Any debris around the root is cleaned off, the coarse exterior bark removed, and the root cut and divided into cube-like pieces to increase its surface area, thereby decreasing the time needed for drying.

References

{{Taxonbar, from=Q1109580 palmatum Plants described in 1759 Taxa named by Carl Linnaeus