Rheum palmatum

Agnia Losina-Losinskaja proposed classifying it in the section Palmata in the Flora SSSR in 1936.{{cite book |last=Лозина-Лозинская |first=Агния Сергеевна |author-link=Agnia Losina-Losinskaja |date=1936 |chapter=Rheum |editor1-last=Комаро́в |editor1-first=Влади́мир Лео́нтьевич |editor1-link=Vladimir Leontyevich Komarov |title=Flora SSSR, Vol. 5 |language=ru |location=Moscow |publisher=Издателство Академии Наук СССР |pages=500–501}} In the 1998 Flora Republicae popularis Sinicae A. R. Li maintains this classification for this species.{{cite journal |last1=Ruirui |first1=Liu |last2=Wang |first2=Ailan |last3=Tian |first3=Xinmin |last4=Wang |first4=Dongshi |last5=Liu |first5=Jianquan |date=2010 |title=Uniformity of karyotypes in Rheum (Polygonaceae), a species-rich genus in the Qinghai-Tibetan Plateau and adjacent regions |url=https://www.researchgate.net/publication/261646487 |journal=Caryologia Firenze |volume=63 |issue=1 |pages=82–90 |doi=10.1080/00087114.2010.10589711 |s2cid=86616077 |access-date=24 March 2019|doi-access=free }}

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It is a perennial herbaceous plant growing to {{cvt|1.5|–|2|m}} tall.{{cite web | title=Rheum palmatum in Flora of China @ efloras.org | website=eFloras.org Home | url=http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200006744 | access-date=2025-07-05}} Its lobed leaves are large, jagged and hand-shaped, growing to {{cvt|40|–|60|cm|0}} wide and long, occasionally to {{cvt|100|cm|0}}. The tiny pink flowers are in panicles up to {{cvt|1.5|m}} tall.{{cite book | last= Hogan | first= Sean | date= 2004 | title= Flora - The Gardener's Bible | location= Willoughby, New South Wales | publisher= Global Book Pub. Pty. Ltd | page= 1141 with photo | isbn= 1-74048-097-X}} Chinese rhubarb has thick, deep roots.{{cite book|last=Foster|first=Steven|title=Desk Reference to Nature's Medicine|year=2006|publisher=National Geographic Society|location=Washington, D.C.|isbn=0-7922-3666-1|pages=104–105}}

The species Rheum tanguticum is closely related to R. palmatum.{{cite book|last=Chevallier|first=Andrew|title=Natural Health: Encyclopedia of Herbal Medicine|year=2000|publisher=Dorling Kindersley|location=New York|isbn=0-7894-6783-6|pages=[https://archive.org/details/encyclopediaofhe00andr/page/127 127]|url-access=registration|url=https://archive.org/details/encyclopediaofhe00andr/page/127}}

R. palmatum can be distinguished from the garden rhubarb R. × hybridum, by size; while garden rhubarb only grows to around a metre in height, Chinese rhubarb can grow to two metres.

R. palmatum has a chromosome count of 2n=22.

It is native in the regions of western China, northern Tibet, and the Mongolian Plateau.

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Rheum tanguticum, Rheum palmatum, R. rhabarbarum and R. officinale and a few others, are all harvested for their roots, which are used as a herbal medicine. Rheum palmatum (or dahuang) is an important crop that has been used in traditional Chinese medicine for over 2,000 years.{{cite journal |last1=Piątek |first1=Marcin |last2=Lutz |first2=Matthias |last3=Wang |first3=Yan |last4=Wang |first4=Shengrong |last5=Kellner |first5=Ronny |title=Thecaphora dahuangis, a new species causing leaf smut disease of the traditional medicinal plant dahuang (Rheum palmatum) in China |journal=Plant Pathology |date=August 2021 |volume=70 |issue=6 |pages=1292–1299 |doi=10.1111/ppa.13385}}

The dried roots of Chinese rhubarb became one of the most prominent items traded along the Silk Road. 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{{snd}}"Russian rhubarb", "Turkey rhubarb", and "Indian rhubarb"{{snd}}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 for "fevers and edema" (swelling caused by fluid retention in the body tissues). It was given its Latin name by Carolus Linnaeus 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 pharmacopoeias.

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

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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 {{convert| 2.5|m|ft|abbr=on}} tall and broad. It is hardy down to {{convert|-20|C|F|abbr=on}}.{{cite web

| url = https://www.rhs.org.uk/Plants/88816/i-Rheum-palmatum-i/Details

| title = RHS Plantfinder – Rheum palmatum | access-date = 23 September 2018}} 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's Award of Garden Merit:-{{cite web

| url= https://www.rhs.org.uk/plants/pdfs/agm-lists/agm-ornamentals.pdf | title = AGM Plants – Ornamental | date = July 2017

| page = 84 | publisher = Royal Horticultural Society | access-date = 27 September 2018}}

• 'Ace of Hearts'{{cite web | url = https://www.rhs.org.uk/Plants/92170/i-Rheum-i-Ace-of-Hearts/Details

| title = RHS Plantfinder – Rheum 'Ace of Hearts' | access-date = 23 September 2018}} – compact cultivar to {{convert| 1.5|m|ft|abbr=on}}

• 'Bowles's Crimson'{{cite web | url = https://www.rhs.org.uk/Plants/93590/i-Rheum-palmatum-i-Bowles-s-Crimson/Details

| title = RHS Plantfinder – Rheum palmatum 'Bowles's Crimson | access-date = 23 September 2018}}

• 'Hadspen Crimson'{{cite web | url = https://www.rhs.org.uk/Plants/277380/i-Rheum-palmatum-i-Hadspen-Crimson/Details

| title = RHS Plantfinder – Rheum palmatum 'Hadspen Crimson' | access-date = 23 September 2018}}

Since it is the roots and rhizome 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 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.

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palmatum

Category:Plants described in 1759

Category:Taxa named by Carl Linnaeus