- Bitter Dock
- Blunt-leaved Dock
- Broad-leaved Dock
- Common Dock
- Red-veined Dock
- Round-leaved Dock
The bitter dog is a perennial non-woody aromatic herb that grows up to anything between two feet and five feet. This European dock with broad obtuse leaves and bitter rootstock has a straight stalk that is greenish in color usually with red streaks.
The herb produces large leaves at the bottom that may be up to 14 inches long and have rounded or heart-shaped bases, while the leaves on the higher branches of the plant are usually smaller and leaner.
Between the period June and September, the bitter dock produces petite green colored flowers in crowded bunches that appear on tall stems at the top of the herb. After the flowers are gone, tiny fruits having a solitary seed appear on the calyx.
These fruits are covered by three deeply jagged valves resembling wings. These seeds possess jagged wing arrangement enabling them to be scattered by wind or water for propagation. Their jagged or toothed configuration also enables the seeds to attach to the animal hides or machinery and be taken to far away places for dispersal.
Bitter dock seeds have the capability to remain dormant for several years before they can germinate under suitable conditions. As a result it is necessary to pull or till the areas where the seeds lie dormant so that they are able to come up to the top soil for germination. The plants can produce seeds in the very first year of their growth and this make it important for detecting them early on for purging.
The scientific name for bitter dock is Rumex obtusifolius and this herb can be easily recognized owing to its extremely big leaves and also because of the fact that some of the leaves at the base of the plant have red stalks. The borders of the bitter dock leaves are crispy or wavy to some extent.
The stalks of the herb have joints or nodes that are covered by a thin membrane resembling paper and called ocrea. It may be mentioned here that such nodes and ocrea are typical of the plants belonging to the Polygonaceae family.
The herb bears large clusters of flowers enclosed in racemes (cone-like structures) that are initially green in color, but transform into reddish hue when they mature. These racemes are held on a solitary stalk that develops higher than the leaves and blossoms right from June to September.
The plants bear fruits each of which enclose a single reddish-brown color seed. Even the seedlings of the bitter dock are easy to recognize as they have egg-shaped or oval leaves with reddish stems.
The curly dock, scientific name Rumex crispus, is almost identical to biter dock (Rumex obtusifolius), with the only exception that the former has thinner and waiver leaves compared to the large round shaped leaves of the latter. In addition, if one scrutinizes the curly dock plant closely, he will find that the calyx of this herb possesses soft borders, while the calyx of the broadleaf dock or the bitter dock has jagged margins.
The bitter dock is a familiar herb in North America where it is usually known as the garden weed that is especially obstinate and spreads outrageously. Presently there are over 20 different species of dock in North America and South America (also known as New World) and some of these were brought in from Europe.
Among these different varieties of dock, the bitter dock, yellow dock and patience dock are prominent. Although these plants differ from one another in terms of size, leaf, flower and fruit, the therapeutic and cookery uses have common characteristics. However, the traditional usage of these plants and their different parts are not evidently differentiated.
However, herbal medicine practitioners were aware of the dock’s therapeutic value as a laxative since the ancient times. Several hundred years later, medical practitioners in England during the Anglo-Saxon period often made use of a blend of dock leaves, other herbs, ale and holy water to treat people who were supposed to have been ailing owing to ‘elf sickness’ allegedly caused by witchcraft.
With the turn of the 17th century, ingestion of a tea prepared with bitter dock roots was considered to provide relief from toothache and treated inflammation when it was used as a wash. According to herbalist Nicholas Culpeper, an extract derived from the bitter dock helped to remove marks or blotches from the skin.
Modern day scientific researches have corroborated the practice of the traditional herbal medical practitioners whereby they used a tea prepared with bitter dock to cure constipation or clear bowel movements. In fact, the bitter dock serves as an effective laxative. The young and tender leaves of this herb may be consumed fresh as a green salad or even be prepared in the same manner as spinach is cooked. On the other hand, the bitter dock root also produces a yellow colorant.
The juice or ‘milk’ extracted from the bitter dock leaf is said to enclose tannins and oxalic acid that are basically astringents. In a number of places in the United Kingdom herbalists treat nettle stings (the irritating sensation caused by ‘nettle’, an herbaceous flowering plant found in Europe, Asia, northern Africa and North America) by forcefully massaging a dock leaf on the area of the sting.
Interestingly enough, the ‘dock leaves’ as the bitter dock leaves are often called are frequently found growing in the vicinity of the nettles. A tincture prepared with the bitter dock leaves is useful in treating menopause problems. And, going by the prescriptions of traditional herbal treatment, roots of the bitter dock plant has a marked detoxifying effect on the liver and it also helps to cleanse the skin of all its blemishes.
Habitat and cultivation
The bitter dock is indigenous to Europe and, hence, is also often referred to as the European dock. However, over the years, this herb has been naturalized all over the United States where it is regarded as a common weed for its vigorous and uncontrolled growth.
Great care needs to be taken while growing the bitter dock from its seedlings. The bitter dock seedlings are unable to face competition from other vegetation and, hence, can only thrive in an open area or disturbed land occupied by permanent vegetation. When bitter docks are found growing in grasslands, be sure that it is owing to lopsided slurry or compost that causes dire plots of land.
In fact, the open pastures left after cutting the shrubs for animal feed are also a reason for the rapid growth of the bitter dock. In addition, over grazing and poaching due to lackadaisical grass management also enables the bitter dock seedlings to come out and flourish rapidly.
It may be mentioned that very less broad-leaved bitter docks grow on grassland that have been nibbled by sheep or which are flooded frequently. On the contrary, they are found often on trampled ground in meadows and in gateways. Bitter docks with broad leaves may also be found among cultivable crops, borders of the fields as well as waste lands.
As far as the soil condition is concerned, the broad-leaved dock, or bitter dock, is very adaptable. It can grow equally well on all kinds of soils, barring majority of acidic soils. The bitter dock prefers both soils having rich nitrogen content as well as poor potassium content.
Nevertheless, a number of recent researches have demonstrated that the growth level of bitter dock increase with increase in the potassium content in the soil. Contrary to this finding, several other studies have shown that soils possessing high potassium content are not suitable for the growth of the bitter dock.
Some people are of the view that bitter dock growing in the grasslands should not be considered to be weeds as these plants contribute to the natural vegetation or fodder in the region. For this reason, this section of people argues that the growth of bitter dock should not be regulated as it is done in the case of other weeds.
They further state that bitter dock encloses certain trace elements that are nutritious for the animal diet and, hence, animals grazing on the grasslands benefit from consuming bitter dock. It may be mentioned here that the leaves of the broad-leaved dock or the bitter dock enclose comparatively high levels of phosphate and potassium, while the magnesium content in the leaves is especially high.
The broad-leaved dock is known to be a host of the potato eelworm( scientific name Ditylenchus destructor) in the United Kingdom. In addition, the bitter dock also functions as substitute hosts for the mangled fly and bean aphis. This herb also promotes the survival of underground larvae like that of the swift moth.
As discussed earlier, the bitter dock blooms between June and September. However, the flowering of the plants is often delayed in the event of removing the shoot quite early or prematurely. A full grown and large bitter dock plant is able to yield as many as 60,000 ripe seeds every year.
From the milk phase on, the seeds come into existence and the unripe seeds would continue to grow on the stems chopped from the plants just some days after the plants bear flowers. The bitter dock plants begin to discard the seeds from the latter phase of summer through to the winter.
However, the bitter dock seeds require some gestation period after ripening in order to germinate properly. If you are propagating the bitter dock from seedlings, then these plants will not produce any flower during the first year of their existence.
The seeds of bitter dock from different populations, diversely branching flower cluster from the same plant and also from different positions on the same panicle vary considerably as far as their germination features are concerned.
The reasons for this variation in germination characteristics are many and may include the size of the seeds, sometimes the depth of the seed coating, often the seeds ripening time and also the maternal factors of the seeds.
Even the destruction of the plant may also have an impact on the development of seed and their germination features. To promote the best germination of the seeds, they require discontinuous temperatures, chilling conditions, addition of nitrates and the seed scarification.
Although the bitter dock seeds are capable of germinating during any season of the year provided the conditions are favorable, they basically germinate on a large-scale during the periods March-April and July-October. The seeds of the bitter dock usually germinate most excellently when they are on the surface of the soil or when in the top 10 mm stratum of the soil.
Nevertheless, the seeds are able to germinate from relatively deeper layers of the soil during summer when the soil is comparatively warm. This is primarily owing to the fact that the bitter dock seeds do not prefer moist soil. The seedlings can come out even from a depth of up to 70 mm in clay dusty soil.
On the other hand, germination of the bitter dock seeds is slow when there is a dense canopy of leaves above the soil. Although the bitter dock seedlings do not grow well in challenging or unfavorable conditions, they enjoy an edge over other crops and grass having superficial or shallow roots once the taproot of these seedlings have gone deep into the ground.
And once the taproots have gone deep into the soil, it is quite difficult to get rid of the bitter dock plants.
While the bitter dock seedlings find it difficult to flourish under competitive conditions, fully grown plants are able to endure or sustain even treading over and mowing. Soon after the plants are trampled or mowed, they send up new shoots and frequent rejuvenation of the plant may even result in the growth of huge thickets.
The parts of the bitter dock plant that lie below the ground include a vertical stalk and a divided taproot with a transition region lying between them. The subterranean stem of the bitter dock often develops up to a length of around 5 cm and it is maintained below the ground by means of the contraction of the root.
During the winter months the broad-leaved dock coils up having undersized shady leaves and a solid taproot. Once the cold is over, the bitter dock produces new leaves quickly in spring and the plant witnesses a productive period that extends for a while.