Rheum rhabarbarum 'MacDonald'

• Common Names
• Description
• Biology
• Taxonomy
• Similar Species
• Bibliography
• More Info
• Notes

Common Names

Description

Family Polygonaceae

Herbs, shrubs , or small trees , sometimes monoecious or dioecious. Stems erect , prostrate , twining , or scandent , often with swollen nodes, striate , grooved , or prickly. Leaves simple , alternate, rarely opposite or whorled , petiolate or subsessile ; stipules often united to a sheath (ocrea) . Inflorescence terminal or axillary , spicate , racemose, paniculate , or capitate. Pedicel occasionally articulate . Flowers small, actinomorphic , bisexual , rarely unisexual . Perianth 3-6-merous, in 1 or 2 series, herbaceous, often enlarged in fruit or inner tepals enlarged, with wings, tubercles , or spines. Stamens usually (3-) 6-9, rarely more; filaments free or united at base ; anthers 2-loculed, opening lengthwise; disk annular (often lobed ) . Ovary superior, 1-loculed; styles 2 or 3, rarely 4, free or connate at lower part. Fruit a trigonous , biconvex , or biconcave achene; seed with straight or curved embryo and copious endosperm.

About 50 genera and 1120 species: worldwide, but primarily N temperate with a few species in tropical regions ; 13 genera (two endemic) and 238 species (65 endemic) in China.Anjen Li, Bojian Bao, Alisa E. Grabovskaya-Borodina, Suk-pyo Hong, John McNeill, Sergei L. Mosyakin, Hideaki Ohba & Chong-wook Park "Polygonaceae". in Flora of China Vol. 5 Page 277. Published by Science Press (Beijing) and Missouri Botanical Garden Press. Online at EFloras.org.

Genus Rheum

Herbs, perennial ; roots fleshy . Stems erect , glabrous or pubescent . Leaves deciduous, mostly basal, alternate, petiolate ; ocrea persistent or deciduous, chartaceous ; blade cordate-ovate to orbiculate or reniform , margins entire , undulate . Inflorescences terminal , paniclelike, pedunculate . Pedicels present. Flowers bisexual , 1-10 per ocreate fascicle, base stipelike; perianth nonaccrescent in fruit, whitish green or pinkish green, campanulate , glabrous; tepals 6, distinct , sepaloid , dimorphic , outer 3 narrower than inner 3; stamens (6-) 9; filaments distinct, free , glabrous; anthers yellow or pinkish, elliptic ; styles 3, erect or deflexed , distinct; stigmas capitate. Achenes exserted, dark brown, winged , 3-gonous, glabrous. Seeds: embryo straight or curved . x = 11.

Species ca. 60: introduced ; temperate regions , Eurasia .Craig C. Freeman "Rheum". in Flora of North America Vol. 5. Oxford University Press. Online at EFloras.org.

Physical Description

Biology

Growth

Culture: Space 24-36" apart.

Soil: Minimum pH: 5.6 • Maximum pH: 7.5

Sunlight: Sun Exposure: Sun to Partial Shade.

Temperature: Cold Hardiness: 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b. (map)

Taxonomy

Similar Species

Members of the genus Rheum

There are approximately 330 species in this genus. Here are just 100 of them:

R. 'Ace of Hearts' (Ace of Hearts Ornamental Rhubarb Rheum) · R. 'Ace of Spades' · R. 'Andrew's Red' · R. 'Dr Baillon' · R. 'Green Knight' · R. 'Holstein Bloodred' · R. 'Kentville' · R. 'Melmerby' · R. 'Timperley Early' (Rhubarb) · R. acuminatum · R. alexandrae · R. alexandrai · R. altaicum · R. aplostachyum · R. australe (Himalayan Rhubarb) · R. austriacum · R. bailloni · R. cantoniense · R. caspicum · R. collinianum · R. compactum · R. compactum var. orientale · R. cordatum · R. coreanum · R. crassinervium · R. crispum · R. cruentum · R. cuneatum · R. darvasicum · R. delavayi · R. dentatum · R. digynum · R. emodi · R. emodium · R. esculentum · R. fedtschenkoi · R. fenestratum · R. forrestii · R. franzenbachii · R. glabricaule · R. globulosum · R. hirsutum · R. hissaricum · R. hotaoense · R. hybridum · R. inopinatum · R. kialense · R. korshinskyi · R. laciniatum · R. leucorrhizum · R. lhasaense · R. likiangense · R. lobatum · R. lucidum · R. macrocarpum · R. macropterum · R. maculatum · R. maximowiczi · R. maximowiczii · R. maximowiezii · R. megalocarpon · R. megalophyllum · R. micranthum · R. microcarpum · R. moorcroftianum · R. muricatum · R. nanum · R. nepalense · R. nobile (Noble Rhubarb) · R. nutans · R. officinale (Chinese Rhubarb) · R. orientale · R. orientixizangense · R. ovatum · R. palaestinum · R. palmatum (Chinese Rhubarb) · R. palmatum ''Rubrum'' · R. palmatum 'Atropurpureum Dissectum' · R. palmatum 'Atropurpureum' · R. palmatum 'Atrosanguineum' (Ornamental Rhubarb) · R. palmatum 'Bowles' Crimson' · R. palmatum 'Da Huang' · R. palmatum 'Flore Rubro' · R. palmatum 'Red Herald mxd' · R. palmatum 'Red Herald' · R. palmatum 'Savill' · R. palmatum var. tanguticum (Rhubarb) · R. palmatum var. palmatum · R. palmatum var. tanguticum (Chinese Rhubarb) · R. palmatum var. tanguticum 'Rosa Auslese' · R. persicum · R. pichonii · R. platylobum · R. plicatum · R. potaninii · R. przewalskyi · R. pumilum · R. qinlingense · R. racemiferum · R. renifolium

Bibliography

• Li Anjen, Kao Tsoching, Mao Zumei & Liu Yulan. 1998. Polygonaceae. In: Li Anjen, ed., Fl. Reipubl. Popularis Sin. 25(1): 1209.
• Chin, T. C. and H. W. Youngken. 1947. The cytotaxonomy of Rheum. Amer. J. Bot. 34: 401-407.

More Info

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Notes

Contributors

• Brands, S.J. (comp.) 1989-2006. Systema Naturae 2000. The Taxonomicon. Universal Taxonomic Services, Amsterdam, The Netherlands. Accessed October 6, 2006.

Identifiers

• Zipcode Zoo Species Identifier: 983724

Footnotes

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