“Rheum (plant)”的意思、由来-开放百科全书

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.

Description

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.

Taxonomy

The genus Rheum was erected in 1753 by Carl Linnaeus,^[4] initially for three species: R. rhaponticum, R. rhabarbarum and R. ribes. Linnaeus did not explain the origin of the genus name. Rheum is usually derived from the Greek rheon,^[5]^[8] mentioned by Dioscorides as an alternative name for medicinal rhubarb; the word rheon is itself thought to be derived from the (old) Persian rewend.^[6] Dioscorides calls the plant rha, but mentions the Romans call it rha ponticum, and it was also called ria or rheon.^[7] 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.^[7]^[8]^[9] (See {{section link|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.^[10] 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.^[11] 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.^[12]

Intergeneric relationships

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.^[14]^[15]

Losinskaja used a slightly different classification in the Flora SSSR in 1936:^[10]

Species

The genus is represented by about 50–60 extant species.^[1]^[15] 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.

This is not necessarily an exhaustive list of recognised species, because there is some disagreement on which taxa should be recognised:

Ecology

Rheum species have been recorded as larval food plants for some Lepidoptera species including brown-tail, buff ermine, cabbage moth, large yellow underwing, and nutmeg moth.{{citation needed|date=March 2019}}

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.^[18] Plants in cultivation are propagated by cutting up the crowns of larger plants and by seeds.

Some species are grown for their ornamental qualities, including R. acuminatum, R. alexandrae, R. australe, R. kialense, R. palmatum, R. rhabarbarum and R. ribes.^[19]

The roots of R. macrocarpum are exploited in the Tian-Shan to make a dye.^[10]

References

1. ^¹²{{cite web |title=Rheum L. |work=Plants of the World Online |publisher=Royal Botanic Gardens, Kew|url=http://www.plantsoftheworldonline.org/taxon/urn:lsid:ipni.org:names:32581-1 |accessdate=2019-03-10 }}
2. ^From Ancient Greek ῥῆον.
3. ^Vegetable Crops Production Guide for the Atlantic Provinces{{dead link|date=May 2015}}
4. ^{{cite web |title=Plant Name Details for Rheum L. |work=The International Plant Names Index |url=http://www.ipni.org/ipni/idPlantNameSearch.do?id=32581-1 |accessdate=2019-03-12 }}
5. ^{{Cite book |last=Hyam |first=R. |last2=Pankhurst |first2=R.J. |year=1995 |title=Plants and their names : a concise dictionary |publication-place=Oxford |publisher=Oxford University Press |isbn=978-0-19-866189-4 |lastauthoramp=yes }}
6. ^¹{{Cite book|title=Why is an Apple a Pomme? A Journey with Words|last=Dunstone|first=Denis|publisher=Lulu Publishing Services|year=2014|isbn=978-1-4834-1859-9}}
7. ^¹{{cite book |last=Osbaldeston |first=Tess Anne |last2=Wood |first2=RPA |date=2000 |title=Dioscorides - De Materia Medica |url=https://archive.org/details/de-materia-medica/page/n392 |location=Johannesburg |publisher=Ibidis Press |page=364, 367 |isbn=0-620-23435-0}}
8. ^J.P. Mallory & D.Q. Adams, Encyclopedia of Indo-European Culture, s.v. "dew" (London: Fitzroy Dearborn, 1997), 158-9.
9. ^{{Cite book |last=Johnson |first=A.T. |last2=Smith |first2=H.A. |year=1972 |title=Plant Names Simplified : Their Pronunciation Derivation & Meaning |publication-place=Buckenhill, Herefordshire |publisher=Landsmans Bookshop |isbn=978-0-900513-04-6 |lastauthoramp=yes }}
10. ^¹²{{cite book |last=Лозина-Лозинская |first=Агния Сергеевна |author-link=Agnia Losina-Losinskaja |date=1936 |chapter=Rheum |chapter-url= |editor1-last=Комаро́в |editor1-first=Влади́мир Лео́нтьевич |editor1-link=Vladimir Leontyevich Komarov |title=Flora SSSR, Vol. 5 |url= |language=Russian |location=Moscow |publisher=Издателство Академии Наук СССР |page=482-501}}
11. ^{{cite book |last=Бородина |first=А.Е. |last2=Грубов |first2=В.И. |last3=Грудзинская |first3=И.А. |last4=Меницкий |first4=Ю.Л. |date=1989 |title=Растения Центральной Азии. По материалам Ботанического института им. В.Л.Комарова. Вып. 9. Ивовые - Гречишные. Л. |trans-title=Plants of Central Asia: plant collections from China and Mongolia, Vol. 9 |url= |language=Russian |location=Moscow |publisher=Издателство Академии Наук СССР |page=77-93}}
12. ^{{cite book |last=Czerepanov |first=Sergeĭ Kirillovich |date=1995 |title=Vascular plants of Russia and adjacent states (the former USSR) |location=Cambridge |publisher=Cambridge University Press |page=412 |isbn=0-521-45006-3}}
13. ^{{Cite journal |last1=Schuster |first1=Tanja M. |last2=Reveal |first2=James L. |last3=Bayly |first3=Michael J. |last4=Kron |first4=Kathleen A. |date=2015 |title=An updated molecular phylogeny of Polygonoideae (Polygonaceae): Relationships of Oxygonum, Pteroxygonum, and Rumex, and a new circumscription of Koenigia |journal=Taxon |volume=64 |issue=6 |pages=1188–1208 |doi=10.12705/646.5 |lastauthoramp=yes }}
14. ^{{cite journal |last=Ruirui |first=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 |access-date=24 March 2019}}
15. ^¹{{Cite journal | doi = 10.1093/aob/mci201| pmid = 15994840| pmc = 4246783| title = Molecular Phylogeny, Recent Radiation and Evolution of Gross Morphology of the Rhubarb genus Rheum (Polygonaceae) Inferred from Chloroplast DNA trnL-F Sequences| journal = Annals of Botany| volume = 96| issue = 3| pages = 489–98| year = 2005| last1 = Wang | first1 = A.| last2 = Yang| first2 = M| last3 = Liu| first3 = J}}
16. ^{{cite book |last=Грубов |first=В.И. |date=1963 |title=Растения Центральной Азии. По материалам Ботанического института им. В.Л.Комарова. Вып. 1. Введение, Папоротники, Библиография. Л. |trans-title=Plants of Central Asia: plant collections from China and Mongolia, Vol. 1 |url= |language=Russian |location=Moscow |publisher=Издателство Академии Наук СССР |page=20}}
17. ^The Plant List
18. ^Rheum rhabarbarum in Flora of North America @. Efloras.org. Retrieved on 2015-05-02.
19. ^{{Cite book | author=Jelitto, Leo; Baumgardt, John Philip; Schacht, Wilhelm; Fessler, Alfred; Epp, Michael E. | authorlink= |author2=Vol 2 | title=Hardy herbaceous perennials | date=1990 | publisher=Timber Press | location=Portland, Or. | isbn=0-88192-159-9 | page=555}}