Rheum (plant)

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Rheum
Rheum rhabarbarum.2006-04-27.uellue.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Caryophyllales
Family: Polygonaceae
Subfamily: Polygonoideae
Genus: Rheum
L.
Species

See text.

Synonyms [1]
  • RhabarbarumFabr.

Rheum [2] is a genus of about 60 herbaceous perennial plants in the family Polygonaceae. Species are native to eastern Europe, southern and eastern temperate Asia, with a few reaching into northern tropical Asia. Rheum is cultivated in Europe and North America. [1] The genus includes the vegetable [3] rhubarb. The species have large somewhat triangular shaped leaves with long, fleshy petioles. The flowers are small, greenish-white to rose-red, and grouped in large compound leafy inflorescences. A number of cultivars of rhubarb have been domesticated both as medicinal plants and for human consumption. While the leaves are slightly toxic, the stalks are used in pies and other foods for their tart flavor.

Contents

Description

Rheum ribes growing in Iran Rivach=Rivas.JPG
Rheum ribes growing in Iran

Rheum species are herbaceous perennials growing from fleshy roots. They have upright growing stems and mostly basal, deciduous leaves growing from short, thick rhizomes. They have persistent or deciduous ocrea. The inflorescences are terminal and panicle-like with pedicels. The hermaphrodite flowers consist of a whitish green to pinkish green, hairless and campanulate (bell-shaped) perianth, composed of six tepals. The outer three tepals are narrower than the inner three and all are sepal-like in appearance. The flowers have nine (sometimes six) stamina inserted on the torus at the base of the peranthium, they are free or subconnate at their base. The anthers are yellow or pinkish green, elliptic in shape. The ovary is simple and triangular shaped with three erect or deflexed styles. The stigmas are head-like. The fruits are a three-sided achene with winged sides, and the seeds are albuminous with a straight or curved embryo.

Seeds Rheumaustrale.jpg
Seeds

Taxonomy

The genus Rheum was erected in 1753 by Carl Linnaeus, [4] initially for three species: R. rhaponticum , R. rhabarbarum and R. ribes . [5] Linnaeus did not explain the origin of the genus name. Rheum is usually derived from the Greek rheon, [6] [7] mentioned by Dioscorides as an alternative name for medicinal rhubarb; the word rheon is itself thought to be derived from the (old) Persian rewend. [7] Dioscorides calls the plant rha, but mentions the Romans call it rha ponticum, and it was also called ria or rheon. [8] It is theorised the Ancient Greek word rha was derived from an ancient Scythian name for the Volga River in Russia, Rā, near from where the plant was supposedly brought. [8] [9] [10] (See Volga River § Nomenclature.)

In 1936 Agnia Losina-Losinskaja in Vladimir Leontyevich Komarov's Flora SSSR recognised 22 native species for the USSR, and furthermore two introduced species, one variety, and one form. [11] The 1989 Plants of Central Asia, dealing with a larger geographical remit, has Alisa E. Grabovskaya-Borodina recognising only 12 species, synonymising a great number. [12] The Vascular plants of Russia and adjacent states of 1995 accepted 17 species for the states of the former USSR, re-recognising many of the taxa as species. [13] In the Flora of China in 2003 Borodina and Bao Bojian recognise 38 species (of which 19 are endemic) in China, including a number Borodina considered synonyms in 1989. [14]

Intergeneric relationships

Rheum is placed in the family Polygonaceae, subfamily Polygonoideae. Within the subfamily, it is in the tribe Rumiceae, along with the two genera Oxyria and Rumex . It is most closely related to Rumex. [15]

Rumiceae

Oxyria

Rumex

Rheum

Infrageneric classification

In the 1998 Flora Republicae popularis Sinicae A. R. Li proposed classifying the Chinese representatives of the genus into five sections. These sections are distinct morphologically, but as of 2010 studies in karyotypy, pollen morphology or molecular data (chloroplast DNA) have failed to elucidate interspecific relationships. [16] [17]

Rheum nanum is the sole species in Losinskaja's section Acaulia Rheum nanum Siev.JPG
Rheum nanum is the sole species in Losinskaja's section Acaulia

Losinskaja used a slightly different classification in the Flora SSSR in 1936: [11]

Species

Rheum tibeticum in May, cultivated in Poland. Rheum tibeticum 2016-04-19 8067.JPG
Rheum tibeticum in May, cultivated in Poland.
Rheum nobile Rheum nobile (photo Bill Baker).jpg
Rheum nobile

The genus is represented by about 50–60 extant species. [1] [17] The many cultivars of culinary rhubarb more usually grown for eating are recognised as Rheum × hybridum in the Royal Horticultural Society's list of recognised plant names. The drug rheum is prepared from the rhizomes and roots of another species, R. officinale or medicinal rhubarb. This species is also native to Asia, as is the turkey rhubarb, R. palmatum . Another species, the Sikkim rhubarb, R. nobile , is limited to the Himalayas.

The centre of diversity for this genus is found in Central Asia. [18]

The following is a partial list of species names, some of which, according to some authorities, are considered synonyms or not fully resolved or accepted: [13] [14] [19]

Ecology

Rheum species have been recorded as larval food plants for some Lepidoptera species such as the buff ermine, Spilarctia luteum , as well as Arctia caja , Hydraecia micacea and Xestia baja . [20]

Rheum species are often the host plants for myrmecophilous caterpillars of the butterfly genus Callophrys ; Callophrys titanus feeds on R. maximowiczii in southern Kazakhstan, [21] C. mystaphia on R. ribes in eastern Turkey, [22] and C. mystaphioides on R. persicum in southwest and central Iran. [23] The caterpillars of the related Lycaena violacea from southeastern Siberia are only known to feed on R. rhabarbarum. [20]

R. ribes leaves are food for the moth Xylena exsoleta in eastern Turkey. [24] Beetles which are specialised herbivores of this plant species in eastern Turkey are a Petrocladus sp. weevil, the jewel beetle Capnodis marquardti , and the leaf beetle Labidostomis brevipennis . [25]

In the Taldy-Bulak valley in the Talas Alatau of Kyrgyzstan, the emerging leaves of R. maximowiczii are an important food source for Himalayan brown bear (Ursus arctos ssp. isabellinus) awakening from hibernation in April. [26]

Uses

Many Rheum species have food and medicinal uses. Some of these uses originated in Asia more than 2,000 years ago. All parts of the plant contain slightly poisonous oxalic acid, but its concentration in the leaf stems or petioles used in food preparation is very low, and their tart flavor instead is caused by nontoxic malic acid. The plants also produce other compounds, including citric acid and anthraquinone glycosides, and the raw or cooked leaf blades are poisonous to humans and livestock if consumed in large enough amounts. [27] Plants in cultivation are propagated by cutting up the crowns of larger plants and by seeds.

Rheum tanguticum (syn. R. palmatum var. tanguticum) Rheum palmatum1C2000.jpg
Rheum tanguticum (syn. R. palmatum var. tanguticum)

Some species are grown for their ornamental qualities, including R. acuminatum, R. alexandrae, R. australe, R. kialense, R. palmatum, R. rhabarbarum and R. ribes. [28]

The roots of R. macrocarpum are exploited in the Tian-Shan to make a dye. [11]

Related Research Articles

<span class="mw-page-title-main">Polygonaceae</span> Knotweed family of flowering plants

The Polygonaceae are a family of flowering plants known informally as the knotweed family or smartweed—buckwheat family in the United States. The name is based on the genus Polygonum, and was first used by Antoine Laurent de Jussieu in 1789 in his book, Genera Plantarum. The name may refer to the many swollen nodes the stems of some species have, being derived from Greek [poly meaning 'many' and gony meaning 'knee' or 'joint']. Alternatively, it may have a different origin, meaning 'many seeds'.

<span class="mw-page-title-main">Rhubarb</span> Species of herbaceous perennial plant with fleshy, sour edible stalks

Rhubarb is the fleshy, edible stalks (petioles) of species and hybrids of Rheum in the family Polygonaceae, which are cooked and used for food. The plant is a herbaceous perennial that grows from short, thick rhizomes. Historically, different plants have been called "rhubarb" in English. The large, triangular leaves contain high levels of oxalic acid and anthrone glycosides, making them inedible. The small flowers are grouped in large compound leafy greenish-white to rose-red inflorescences.

<i>Rumex</i> Genus of plants

The docks and sorrels, genus Rumex, are a genus of about 200 species of annual, biennial, and perennial herbs in the buckwheat family, Polygonaceae. Members of this genus are very common perennial herbs with a native almost worldwide distribution, and introduced species growing in the few places where the genus is not native.

<i>Rumex acetosella</i> Species of flowering plant

Rumex acetosella, commonly known as red sorrel, sheep's sorrel, field sorrel and sour weed, is a species of flowering plant in the buckwheat family Polygonaceae. Native to Eurasia and the British Isles, the plant and its subspecies are common perennial weeds. It has green arrowhead-shaped leaves and red-tinted deeply ridged stems, and it sprouts from an aggressive and spreading rhizome. The flowers emerge from a tall, upright stem. Female flowers are maroon in color.

<i>Rheum palmatum</i> Species of flowering plant

Rheum palmatum is a species of flowering plant in the knotweed family Polygonaceae. It is commonly called Chinese rhubarb, ornamental rhubarb, Turkey rhubarb or East Indian rhubarb.

Chinese rhubarb can mean either of two species of rhubarb, genus Rheum:

<i>Rheum nobile</i> Species of flowering plant

Rheum nobile, the Sikkim rhubarb or noble rhubarb or पदमचाल, is a giant herbaceous plant native to the Himalaya, from northeastern Afghanistan, east through northern Pakistan and India, Nepal, Sikkim, Bhutan, and Tibet to Myanmar, occurring in the alpine zone at 4000–4800 m altitude.

<i>Rheum officinale</i> Species of flowering plant

Rheum officinale, the Chinese rhubarb, or Indian rhubarb is a rhubarb from the family Polygonaceae native to China. In Chinese it is called yào yòng dà huáng, literally meaning medicinal rhubarb.

<span class="mw-page-title-main">Petiole (botany)</span> Stalk holding a leaf to its stem

In botany, the petiole is the stalk that attaches the leaf blade to the stem. It is able to twist the leaf to face the sun, producing a characteristic foliage arrangement, and also optimizing its exposure to sunlight. Outgrowths appearing on each side of the petiole in some species are called stipules. The terms petiolate and apetiolate are applied respectively to leaves with and without petioles.

<span class="mw-page-title-main">Emodin</span> Chemical compound

Emodin (6-methyl-1,3,8-trihydroxyanthraquinone) is a chemical compound, of the anthraquinone family, that can be isolated from rhubarb, buckthorn, and Japanese knotweed. Emodin is particularly abundant in the roots of the Chinese rhubarb, knotweed and knotgrass as well as Hawaii ‘au‘auko‘i cassia seeds or coffee weed. It is specifically isolated from Rheum palmatum L. It is also produced by many species of fungi, including members of the genera Aspergillus, Pyrenochaeta, and Pestalotiopsis, inter alia. The common name is derived from Rheum emodi, a taxonomic synonym of Rheum australe, and synonyms include emodol, frangula emodin, rheum emodin, 3-methyl-1,6,8-trihydroxyanthraquinone, Schüttgelb (Schuttgelb), and Persian Berry Lake.

<i>Oxyria</i> Genus of flowering plants

Oxyria is a genus of plants in the family Polygonaceae with three accepted species as of March 2019. It has a circumboreal distribution.

<i>Calligonum</i> Genus of flowering plants

Calligonum is a genus of plants in the family Polygonaceae with about 80 species across the Mediterranean Sea region, Asia and North America.

<i>Rheum rhabarbarum</i> Species of plant

Rheum rhabarbarum is a species of flowering plant in the family Polygonaceae, native to a region stretching from southern Siberia to north and central China. It has been harvested from the wild for centuries for its root, which was harvested for use as a popular medicine in Europe and Asia. It was later cultivated for its root in England and Russia. It is considered to be one of the species involved in the development of culinary rhubarb, for which the scientific name R. rhabarbarum is sometimes (erroneously) used.

<i>Rheum australe</i> Species of flowering plant

Rheum australe, synonym Rheum emodi, is a flowering plant in the family Polygonaceae. It is commonly known as Himalayan rhubarb, Indian rhubarb and Red-veined pie plant. It is a medicinal herb used in the Indian Unani system of medicine, and formerly in the European system of medicine where it was traded as Indian rhubarb. The plant is found in the sub-alpine and alpine Himalayas at an altitude of 4000 m.

<i>Rheum maximowiczii</i> Species of flowering plant

Rheum maximowiczii is a large herbaceous perennial plant species in the genus Rheum (rhubarbs) from the mountains of Central Asia where it grows in Kazakhstan, eastern Uzbekistan, Tajikistan, Kyrgyzstan and northeastern Afghanistan.

<i>Rheum ribes</i> Species of plant

Rheum ribes, the Syrian rhubarb or currant-fruited rhubarb, or warty-leaved rhubarb, is an edible wild rhubarb species in the genus Rheum. It grows between 1000 and 4000 m on dunite rocks, among stones and slopes, and is now distributed in the temperate and subtropical regions of the world, chiefly in Western Asia to Afghanistan and Pakistan and also in ladakh(Kargil) region of India. The Syrian rhubarb is a partially commercial vegetable collected from wild patches in Eastern and Southern Anatolia, Northern Iraq and partly Northwestern Iran in early spring. Rheum ribes is considered as a valuable medicinal species in herbal medicine.

<i>Rheum rhaponticum</i> Species of flowering plant

Rheum rhaponticum, the false rhubarb, rhapontic rhubarb or rhapontic, is a plant species in the genus Rheum found in the wild. It is the only Rheum species found only in Europe, and is now restricted to the Rila mountain range in south-western Bulgaria. It was introduced to other countries in Europe. It is considered to be one of the parents of the modern culinary rhubarb.

Agnia Sergeyevna Losina-Losinskaja (1903–1958) was a Soviet botanist. Her family name is also transcribed as Lozina-Lozinscaia, and Lozina-Lozinskaja.

Rheum lhasaense is a plant from eastern Tibet belonging to the genus Rheum in family Polygonaceae. It is a mid-sized rhubarb species with triangular leaves and spherical fruit.

<i>Rheum webbianum</i> Species of plant

Rheum webbianum is a species of herbaceous perennial rhubarb-relative in the family Polygonaceae from the southwestern Himalayan region, known in (Indian) English as Indian rhubarb, Gilgiti rhubarb or small Himalayan rhubarb.

References

  1. 1 2 3 "Rheum L." Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 2019-03-10.
  2. ↑ From Ancient Greek ῥῆον.
  3. ↑ Vegetable Crops Production Guide for the Atlantic Provinces [ dead link ]
  4. ↑ "Plant Name Details for Rheum L." The International Plant Names Index . Retrieved 2019-03-12.
  5. ↑ Linnaeus, Carolus (1753). "Rheum ribes". Species Plantarum, Tomus I. Stockholm: Impensis Laurentii Salvii. Retrieved 2019-03-11.
  6. ↑ Hyam, R. & Pankhurst, R.J. (1995). Plants and their names : a concise dictionary. Oxford: Oxford University Press. ISBN   978-0-19-866189-4.
  7. 1 2 Dunstone, Denis (2014). Why is an Apple a Pomme? A Journey with Words. Lulu Publishing Services. ISBN   978-1-4834-1859-9.
  8. 1 2 Osbaldeston, Tess Anne; Wood, RPA (2000). Dioscorides - De Materia Medica. Johannesburg: Ibidis Press. p.  364, 367. ISBN   0-620-23435-0.
  9. ↑ J.P. Mallory & D.Q. Adams, Encyclopedia of Indo-European Culture, s.v. "dew" (London: Fitzroy Dearborn, 1997), 158-9.
  10. ↑ Johnson, A.T. & Smith, H.A. (1972). Plant Names Simplified : Their Pronunciation Derivation & Meaning. Buckenhill, Herefordshire: Landsmans Bookshop. ISBN   978-0-900513-04-6.
  11. 1 2 3 Лозина-Лозинская, Агния Сергеевна (1936). "Rheum". In Комаро́в, Влади́мир Лео́нтьевич (ed.). Flora SSSR, Vol. 5 (in Russian). Moscow: Издателство Академии Наук СССР. pp. 482–501.
  12. ↑ Бородина, А.Е.; Грубов, В.И.; Грудзинская, И.А.; Меницкий, Ю.Л. (1989). Растения Центральной Азии. По материалам Ботанического института им. В.Л.Комарова. Вып. 9. Ивовые - Гречишные. Л.[Plants of Central Asia: plant collections from China and Mongolia, Vol. 9] (in Russian). Moscow: Издателство Академии Наук СССР. pp. 77–93.
  13. 1 2 Czerepanov, Sergeĭ Kirillovich (1995). Vascular plants of Russia and adjacent states (the former USSR). Cambridge: Cambridge University Press. p. 412. ISBN   0-521-45006-3.
  14. 1 2 Bojian (包伯坚), Bao; Grabovskaya-Borodina, Alisa E. (2003). "Rheum". In Zhengyi (吴征镒), Wu; Raven, Peter H.; Deyuan (洪德元), Hong (eds.). Flora of China, Vol. 5. Beijing: Science Press. p. 341.
  15. ↑ Schuster, Tanja M.; Reveal, James L.; Bayly, Michael J. & Kron, Kathleen A. (2015). "An updated molecular phylogeny of Polygonoideae (Polygonaceae): Relationships of Oxygonum, Pteroxygonum, and Rumex, and a new circumscription of Koenigia". Taxon. 64 (6): 1188–1208. doi:10.12705/646.5.
  16. ↑ Ruirui, Liu; Wang, Ailan; Tian, Xinmin; Wang, Dongshi; Liu, Jianquan (2010). "Uniformity of karyotypes in Rheum (Polygonaceae), a species-rich genus in the Qinghai-Tibetan Plateau and adjacent regions". Caryologia Firenze. 63 (1): 82–90. doi: 10.1080/00087114.2010.10589711 . S2CID   86616077 . Retrieved 24 March 2019.
  17. 1 2 Wang, A.; Yang, M; Liu, J (2005). "Molecular Phylogeny, Recent Radiation and Evolution of Gross Morphology of the Rhubarb genus Rheum (Polygonaceae) Inferred from Chloroplast DNA trnL-F Sequences". Annals of Botany. 96 (3): 489–98. doi:10.1093/aob/mci201. PMC   4246783 . PMID   15994840.
  18. ↑ Грубов, В.И. (1963). Растения Центральной Азии. По материалам Ботанического института им. В.Л.Комарова. Вып. 1. Введение, Папоротники, Библиография. Л.[Plants of Central Asia: plant collections from China and Mongolia, Vol. 1] (in Russian). Moscow: Издателство Академии Наук СССР. p. 20.
  19. ↑ "The Plant List: Rheum". Royal Botanic Garden, Kew and Missouri Botanic Garden. Retrieved 3 April 2019.
  20. 1 2 Savela, Markku. "Rheum". Lepidoptera and some other life forms. Markku Savela. Retrieved 16 March 2019.
  21. ↑ Savela, Markku. "Callophrys". Lepidoptera and some other life forms. Markku Savela. Retrieved 5 April 2019.
  22. ↑ Van Gölü Havzasında Kelebek Çeşitliliği (Diversity of the butterflies in Van Lake Basin East Turkey) by Muhabbet Kemal, 2008
  23. ↑ Krupitsky, Anatoly; Kolesnichenko, Kirill (March 2013). "A new species of the Callophrys mystaphia Miller, 1913—group from Iran (Lepidoptera: Lycaenidae: Eumaeini)". Zootaxa. 3619 (4): 460–466. doi:10.11646/zootaxa.3619.4.4 . Retrieved 5 April 2019.
  24. ↑ Muhabbet Kemal, Halil Özkol & Lokman Kayci (2008), Xylena Ochsenheimer in East Turkey with new provincial records and larval food-plants (Noctuidae, Lepidoptera), in Miscellaneous Papers, Centre for Entomological Studies Ankara, no: 139-140, 20.03.2008
  25. ↑ Korotyaev, Boris A.; Gültekin, Levent; Volkovitsh, Mark G.; Dorofeyev, Vladimir I.; Konstantinov, Alexander S. (January 2016). "Bioindicator beetles and plants in desertified and eroded lands in Turkey". Journal of Insect Biodiversity. 4 (1): 28, 29, 34, 42. doi: 10.12976/jib/2016.4.1 . Retrieved 16 March 2019.
  26. ↑ Vladimir Kolbintsev & Kurt Vickery (April 2013). The Tulips of the Tien Shan (PDF) (Report). Greentours Natural History Holidays. Retrieved 2 April 2019.
  27. ↑ Rheum rhabarbarum in Flora of North America @. Efloras.org. Retrieved on 2015-05-02.
  28. ↑ Jelitto, Leo; Baumgardt, John Philip; Schacht, Wilhelm; Fessler, Alfred; Epp, Michael E. (1990). Hardy herbaceous perennials. Vol. 2. Portland, Or.: Timber Press. p. 555. ISBN   0-88192-159-9.
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