The diverse Dock or Buckwheat family (Polygonaceae) consists of over 800 species, which are represented to the backyard gardener as one of those common, pesky weeds known as Dock Rumex sp., Sorrel Rumex acetosella, or Wireweed Polgonum aviculare. However, the family boasts numerous attractive exotic ornamentals, (eg the small brightly flowering herb Polygonum affine and the strikingly beautiful tree Long John Triplaris surinamensis), Tasmanian natives used for bush tucker, (eg Swamp Dock Rumex brownii and the Climbing Lignum Muehlenbeckia adpressa), Rhubarb Rheum rhaponticum as well as the grain and green manure crop Buckwheat Fagopyrum esculentum.
Spending time on the docks reveals an intriguing set of attributes spread amongst the diverse array of family members.
The Tasmania native Docks (Swamp Dock, Mud Dock Rumex bidens and Native Dock Rumex dumosus) have distinctive flower heads, which can simply be used to add texture and colour to your bush tucker patch. These and the exotic docks are generally considered as weedy opportunists, without the gardener being aware of their important use as Vitamin C rich, leafy greens and traditional medicines. As a precautionary note, they, like rhubarb, shouldn't be consumed in large amounts due to their high levels of oxalic and tannic acids. A mild laxative effect can be experienced following an over indulgence.
Of concern to the farmer and gardener alike, are their invasive abilities resulting from their hooked seedpods, which can easily attached themselves to marsupial fur or sheep fleeces. An astute gardener always considers their presence as a bonus due to their ability to enhance the soil fertility and provide nutrient rich compost ingredients. This is a consequence of their long taproots, which extracts and stores from deep within the soil, leached nutrients and minerals.
Although the small native Swamp Dock prefers a moist forest habitat it tends to be much larger when grown in a cultivated site or bush tucker patch. A few plants can produce enough succulent leaves and stout stems to replace the traditional Silver Beet crop with a superior flavoured green. Besides using it in stir-fries, enjoy it as a seasoning for soups, omelettes or roast lamb.
The exotic Curled Dock Rumex crispus is also a favourite green and the leaf stems can be sweetened with sugar and cooked as an alternative to Rhubarb. Mixing stewed apples or pears with cooked diced stems can provide a rhubarb-flavoured tang to the traditional apple pie or tart.
Medicinally, the crushed leaves can be applied as a poultice to open wounds and used to take the heat out of skin infections. Root decoctions are used to treat gout.
Sheep Sorrel Acetosella vulgaris, a weed of sandy soils, has a reputation as a tasty green, dating back to Henry the Eighth. A small amount of the bitter tonic 'sorrelade' which was made from fresh leaves is used as a diuretic, for upset stomachs or menstrual discomfort. Stock can be poisoned if they ingest excessive amounts of the oxalates found in the leaves.
Another dock plant called 'Native Hops' Acetosa vesicaria forms, after rains, rosy red blankets across vast tracks of sandy outback desert. So prolific is this weed, that it is now viewed as a spectacular floral tourist attraction. It was introduced from North Africa, where it is still popular Bedouin tribal green.
Different from the docks is the drought tolerant native vine Climbing Lignum Muehlenbeckia adpressa. It is an ideal screening plant for growing on trellises. From the shade and moisture loving Macquarie Vine, M.gunnii, edible acid tasting berries can be harvested as bush tucker. The seeds can be ground into nutritious flour.
The Europeans have cropped the triangular seeds for millenniums due to buckwheat's high protein content. It has also served as a nutritious stock feed. Roasted seeds (called kasha) can be prepared like rice or alternatively ground to form buckwheat flour. The flour is traditionally used for Russian type pancakes (blinis) or similar Breton versions (galettes). They have a delicious and distinctly grainy flavour combining temptingly with vegetables. Buckwheat has developed a reputation as an allergy free alternative for those who are demanding gluten free diets, replacing cereals such as wheat, oats, rye etc.
Surprisingly both wireweed and buckwheat flowers are a well-proven sources of honey production. More significantly to the organic gardener is this disease resistant plant's ability to loosen compacted clay soils and generate voluminous quantities of green manure. It thrives in low phosphate soils, of which cereals crops are intolerant. Since it concentrates phosphates composting it or green cropping will enhance the soil's organic phosphate levels.
Closely related to the docks, the tropical street tree 'Long John' is endemic to South America. This tree presents an unforgettable picture of dense shuttlecock like clusters of white flowers turning into bright red blooms as they age. Since thousands of fierce stinging ants often hollow out their stems they command unusual respect. Amazonian Indians exploit these ants by channelling them into selected branches to be hollowed out for tobacco pipes.
The weird shrub Homalocladium platycladium aptly named the Tapeworm Plant proved a great garden favourite in Edwardian glasshouses. The twisted and jointed, flattened green stems (cladodes), with their tiny leaves and red berries, looked just like real tapeworms.
An unexpected relative of the dock is the tolerant, coastal American tree, known as Seagrape, Coccoloba uvifera. Its name derives from the edible, reddish fruits that hang down in grape like clusters, which can be made into 'seaside jelly' or wine. It is a popular small tree for Florida landscapes providing street shade, windbreaks and a tropical look near the sea.
The bark was once used in Mexico for school writing paper. Its craft wood is prized for the fine polish it takes and the red dye it exudes when boiled. Its gum is renowned for easing throat ailments, while roots decoctions treat dysentery successfully.
Hopefully, when next targeting dock 'weeds' in your garden, some section of this insight into the Docks, will flash into your mind, adding interest and understanding towards your gardening chore.
Phil Watson