Latin name: Rumex crispus
Source material: Pollen
Common names: Yellow Dock, Curled Dock, Curly dock, Narrowleaf dock, Sour dock
See also: Sheep Sorrel w18 (R. acetosella)
Yellow Dock is a perennial flowering plant in the family Polygonaceae, native to Europe, including Britain, and western Asia. It has become a serious invasive species in many areas, including throughout North America, southern South America, New Zealand and parts of Australia, by spreading through the seeds contaminating crop seeds, and sticking to clothing. (1)
Dock is a perennial growing to 1 m by 0.3 m. The mature plant is a reddish brown colour, and produces a stalk that grows to about 1 m high. It has smooth leaves shooting off from a large basal rosette, with distinctive waved or curled edges. The pointed light green leaves are lanceolate to oblong-lanceolate in shape, and have predominantly wavy margins. The basal leaves are 5-36 cm long and 2-12 cm wide. The flowering portion is placed at the top of the plant has many dense flower clusters. On the stalk drooping flowers are loosely whorled in panicled racemes. The seeds are produced in clusters on branched stems, with the largest cluster being found at the apex.
Yellow dock is in flower from June to October. The flowers are hermaphrodite (have both male and female organs) and are wind pollinated. The seeds ripen from July to October. The calyx (fruit) is a pointed three-angled and heart-shaped nut. The seeds are shiny, brown and encased in the calyx of the flower that produced them. This casing enables the seeds to float on water and get caught in wool and animal fur, and this helps the seeds to spread to new locations.
It grows almost anywhere, but particularly in grassy places, waste ground, and roadsides and near sand dunes. It is a serious weed of agriculture.
The leaves, stems and seeds are eaten raw or cooked. The roasted seed has been used as a coffee substitute. These plants can contain quite high levels of oxalic acid, which is what gives the leaves of many members of this genus an acid-lemon flavour.
Antigenic proteins of 40, 38, 24, and 21 kDa have been detected. (2)
No allergens have been characterised to date.
Cross-reactivity could be expected between species of the family Polygonaceae.
Similar allergenic components of Ragweed pollen have been detected in Yellow dock pollen. In a preliminary study, sera of two patients with IgE antibodies to Ragweed pollen antigens also reacted to a similar 40 kDa component in Yellow dock pollen. Of 109 patients with asthma, of 22 patients who were sensitised to a crude extract of Ragweed pollen, 18 (81.8%) also reacted to the crude extract of Yellow dock pollen. (2)
Anecdotal evidence suggests that asthma, allergic rhinitis and allergic conjunctivitis are common following exposure to pollen from Yellow dock; however, few specific studies have been reported to date. (3, 4)
In a study examining aeroallergen sensitization rates in military children in Texas with rhinitis, of 209 patients, 17% were sensitised to Yellow Dock or Sorrel. (4)
In an aeroallergen study in Bitlis, Turkey, Rumex spp. was one of the pollens responsible for the greatest amounts of pollens. (5) Pollen from Rumex spp. has also been reported in aerobiological studies in Lublin, Eastern Poland, (6) in Dehra Dun, in India, (7) and evaluated in a number of European communities (London, Leiden, Brussels, Munich and Marseilles). (8) Rumex was also reported to be one of 22 types of pollen found in the air of Athens, Greece, mostly during the March-July period. (9)
Compiled by Dr Harris Steinman, firstname.lastname@example.org
- Wikipedia contributors, "Curled Dock," Wikipedia, The Free Encyclopedia, http://en.wikipedia.org/w/index.php?title=Curled_Dock&oldid=232831041 (accessed August 22, 2008).
- Shen HD, Chang LY, Gong YJ, Chang HN, Han SH. A monoclonal antibody against ragweed pollen cross-reacting with yellow dock pollen. [Chinese] Zhonghua Min Guo Wei Sheng Wu Ji Mian Yi Xue Za Zhi 1985;18(4):232-9.
- Solomon WR. An appraisal of Rumex pollen as an aeroallergen. J Allergy 1969;44:25-36.
- Calabria CW, Dice J. Aeroallergen sensitization rates in military children with rhinitis symptoms. Ann Allergy Asthma Immunol 2007;99(2):161-9.
- Celenk S, Bicakci A. Aerobiological investigation in Bitlis, Turkey. Ann Agric Environ Med 2005;12(1):87-93.
- Weryszko-Chmielewska E, Piotrowska K. Airborne pollen calendar of Lublin, Poland. Ann Agric Environ Med 2004;11(1):91-7.
- Singh BP, Singh AB, Nair PK, Gangal SV. Survey of airborne pollen and fungal spores at Dehra Dun, India. Ann Allergy 1987;59(3):229-34.
- Spieksma FT, Charpin H, Nolard N, Stix E. City spore concentrations in the European Economic Community (EEC). IV. Summer weed pollen (Rumex, Plantago, Chenopodiaceae, Artemisia), 1976 and 1977. Clin Allergy 1980;10(3):319-29.
- Apostolou EK, Yannitsaros AG. Atmospheric pollen in the area of Athens. Acta Allergol 1977;32(2):109-17.