rheum


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Related to rheum: Rheum officinale

rheum

a watery discharge from the eyes or nose

Rheum

 

(rhubarb), a genus of plants of the family Polygonaceae. Rhubarbs are large perennial herbs. The flower stalk is solid or hollow and reaches a height of 1.5–2 m. The radical leaves, which have long, succulent petioles, form a rosette and are very large and usually entire. (R. palmatum var. tanguticum has five- to seven-lobed leaves.) The inflorescence is panicled or spicate. The flowers are bisexual; male flowers sometimes occur. The fruit is a brown, three-angled, winged achene.

Rhubarb is native to Southeast Asia, northern Mongolia, northern China, the Altai region, and Siberia. Of the approximately 30 known species (according to other data, 49), 22 are found in the USSR. Some species are cultivated as vegetable, medicinal, and tannin-yielding plants. The most commonly cultivated species are R. undulatum, R. compactum, and the garden rhubarb (R. rhaponticum).

Rhubarb, a cold-resistant plant, can tolerate spring frosts of - 10°C. Its growth is triggered by the thawing of the soil. The plant grows well at a temperature of 8°-10°C and requires little light. The soil must be fertile and damp, but there should be no standing water.

The leaf stalks, which are edible, contain as much as 2.5 percent sugars and approximately 3.5 percent organic acids (primarily malic, citric, oxalic, and succinic acids). They also contain potassium, calcium, phosphorus, and magnesium salts. Rhubarb is used to make compote, jelly, jam, and wine. The roots of R. palmatum var. tanguticum contain the laxatives emodin, chrysophanic acid, and anthracene glycosides; they are used medicinally in the form of powders, tablets, alcohol tinctures, and syrups.

Rhubarb is propagated from seeds, seedlings, or pieces of rhizome. The first crop is obtained two years after planting. The stalks, which measure 25–70 cm long and 1.5–4 cm thick, are gathered (by breaking, cutting, or mowing) from early May through the first ten days of June. The yield in the sixth or seventh year is 250–300 quintals per hectare. An early harvest (by ten to 15 days), with twice the normal yield, may be obtained by covering the plants with a synthetic film. Rhubarb can also be raised in hothouses from three- or four-year-old rhizomes.

Z. S. LEZHANKINA and N. I. OSINA

References in periodicals archive ?
The 2010 rheumatoid arthritis classification criteris Involvement of swollen and tender joints Points 1 medium-large joint 0 2-10 medium-large joints 1 1-3 small joints 2 4-10 small joints 3 Greater than 10 joints (at least 1 5 must be small) Serology Neither RF nor ACPA positive 0 one low-positive titer on at least one test 2 one high-positive titer on at least one test 3 Duration of synovitis Less than 6 weeks 0 6 weeks or longer 1 Acute-phase reactants Neither CRP nor ESR abnormal 0 Abnormal CRP or abnormal ESR 1 Source: Arthritis Rheum.
D A W M van der Windt and L M Bouter Ann Rheum Dis 2003; 62: 385-387.
Several species of the genus Rheum (Polygonaceae) such as Rheum palmatum, R.
In cold regions you can always cheat by supplementing borderline plants with tropical-looking ones that are hardier than they appear, such as yuccas, figs, gunnera or the giant rhubarb, Rheum palmatum.
The effect of mini-dose aspirin on renal function and uric acid handling in elderly patients," Arthritis Rheum, vol.
Even more worthwhile for garden accents are the ornamental rhubarbs (Rheum australe and Rheum palmatum).
Other tropical-effect plants include: Tree ferns, phoenix palms, yuccas, cordylines, Redgersia pinnata, Gunnera manicata, Rheum palmatum, cycads, citrus (lemons and calamondin orange), bamboos, Filipendula rubra, Ligularia, gloriosa lily and Fatsia japonica.
The American College of Rheumatology has also endorsed self-management training for OA patients in the society's OA management recommendations (Arthritis Rheum.
58 for RA, The investigators suggested that exposure to the industrial solvents used for extracting caffeine before the mid-1970s might have played a role (Arthritis Rheum.
American College of Rheumatology Guidelines (2002) Arthritis Rheum 46: 328-346.
Baggett's poster presentation, entitled "Anthraquinones from rheum palmatum displaying estrogen activity," involved the isolation of selective ER beta compounds from Rheum palmatum, one of the botanical agents in the Company's lead drug candidate, MF101.