Polygonaceae Part 1: Different Dreadful Docks or not?

Dock and Ragwort, two of the most notorious weeds!

This week it is mainly about the title or the Dock and Sorrel plants which forms a large genus in the family of the Polygonaceae or the Dock and Knotweeds family. 

The Knotweeds will be in next week’s blog.

Why are Docks Dreadfull?

First I like to get all of the negative things out of the way, before we talk about the positive things:

  • Dock’s tap root are long, slender and deep, going half a metre down; any stray piece left can sprout into a new plant.
  • Each dock can produce 30.000 or more seeds a year, and these can lay dormant for up to fifty years.
  • They can pass unharmed through a horse’s stomach and germinate. If we use their manure as a mulch or soil-improver it is notoriously full of nettles and dock seeds.
  • Adding horse manure and composting it in your own garden heap may help to reduce the weed content, but only if your heap gets hot enough to kill the seeds.

It is no wonder it is so hard to eliminate.

The Weeds Act of 1959 gives R. crispus and R.  x obtusifolius or broad-leaved dock as the two injurious weeds along with common ragwort, spear thistle and creeping or field thistle.

  • Docks are an indicator of very poor, acid soil so improving the soil will mostly get rid of them!
  •  Or digging isolated specimens out as only the top few inches of rootstock have powers of regeneration.

The genus Rumex or Docks are not very easy to identify and Stace provides a general key as well as a Key A to Key C to identify the 23 species present in the British Isles.

This genus is then divided in 3 subgenera where the 2 first subgenera are dioecious ( subg. acetosella and subg. acetosa) and the third subgenus is rumex, which is bisexual and we so well know as the ‘real’ dock.

This has 19 species and many hybrids. 

To identify them in the field, you will need a hand lens. The fruits (called fruiting tepals) are very diagnostic in each different species .

Now for the more positive uses of the Docks and Sorrels:

Edible uses:

These plants are edible. Some species with particularly high levels of oxalic acid are called sorrels (including sheep’s sorrel, Rumex acetosella, common sorrel, Rumex acetosa, and French sorrel, Rumex scutatus), and some of these are grown as leaf vegetables or garden herbs specifically for their acidic taste.

  • Common sorrel has been cultivated for centuries. The leaves may be puréed in soups and sauces or added to salads.
  • Throughout eastern Europe, wild or garden sorrel is used to make sour soups, stewed with vegetables or herbs, meats or eggs.
  • In rural Greece, it is used with spinach, leeks, and chard in spanakopita.
  •  In Albania, the leaves are simmered and served cold marinated in olive oil, or as an ingredient for filling byrek pies (byrek me lakra).
  • In Armenia, the leaves are collected in spring, woven into braids, and dried for use during winter. The most common preparation is aveluk soup, where the leaves are rehydrated and rinsed to reduce bitterness, then stewed with onions, potatoes, walnuts, garlic and bulgur wheat or lentils, and sometimes sour plums.

When we see the flowering spikes of Rhubarb we might well be forgiven to think this is a type of Rumex. But Rhubarb or Rheum x rhabarbarum is the best well-known cultivated+ one and the ornamental grown Rhubarb (R. palmatum) is also edible but both species are not native.

Medicinal uses:

Hedgerow medicine has a nice chapter about the Curled Dock (Rumex crispus) which is one of the two common docks among the 5 official ‘injurious weeds’ in Britain, but curled dock has long-recognised redeeming qualities as:

  • a detoxifying liver and bowel herb,
  • a laxative and a blood cleanser.
  • The root is effective for many chronic toxic skin conditions, including acne and boils, eczema and sunburn,
  • not forgetting the most famous use of dock leaves for relieving the burning caused by nettle stings
  • In traditional Austrian medicine, R. alpinus leaves and roots have been used internally for treatment of viral infections.

Other uses:

  • Rumex species are used as food plants by the larvae of a number of Lepidoptera species, and are the only host plants of Lycaena rubidus
  • Broad-leaved dock (Rumex obtusifolius) used to be called butter dock because its large leaves were used to wrap and conserve butter
  • There is at least one ornamental sorrel grown in gardens which is the Wood Dock or  R. sanguineus var. sanguineus with blood-red leaf-veins which is a rare garden escape or casual.
  • The leaves of R. acetosa are eaten by the larvae of several species of Lepidoptera (butterfly and moth) including the blood-vein moth.
  • Rumex scutatus is used as a culinary herb. Its common names include French sorrel, buckler sorrel, shield-leaf sorrel, and sometimes the culinary name“green-sauce”.    It is sometimes preferred for culinary uses to garden cultivars of Rumex acetosa, common sorrel.
  • The dried, rusty coloured dock stems are very attractive in dry flower arrangements!
common sorrel with buttercups and meadow foxtail form a magic picture in early summer!
common sorrel with buttercups and meadow foxtail form a magic picture in early summer!

Hope you found learning about these Dreadful Docks interesting and see you in the next blog?

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