The region of South Africa receiving winter rainfall (‘the Cape’) is an area with exceptional plant biodiversity and a high degree of endemism. It contains many edible species, which were historically foraged rather than cultivated, and were part of the food cultures of nomadic people, for example the Bushmen like the San people who were mainly hunter-gatherers.
However, from 1650 onward, settlers introduced fruit and vegetable cultivars, which over time have come to form the basis of modern agriculture and cuisine throughout the country. The culture of foraging for and use of Cape wild foods has now almost completely been displaced, resulting in significant loss of knowledge.
Dune Spinach (Tetragonia decumbens) is a low growing spreading perennial indigenous to the coastline of South Africa receiving winter rainfall, stretching from the border on the West Coast to the Kei River on the East.
It has green glistening slightly plump succulent rounded opposite leaves that have tiny water storage cells on their surface. This gives them a slightly rough texture when eaten raw. They produce yellow sweetly fragrant flowers and many four-winged seeds. They are early stabilizers of sand dunes and often creep into surrounding shrubs.
There are several other species of Tetragonia that occur on the coast as well as inland over far more extensive parts of the Cape. Some are also creeping in nature, like T fruticosa, and others are more woody and shrub-like. All have smaller and narrower edible leaves than T. decumbens, and can be used in much the same way in cooking.
Though this plant is not at risk of extinction, it is a greatly under-utilized vegetable that shows great promise as an undemanding resilient winter rainfall perennial crop. It has never been farmed, but is being piloted for possible commercial cultivation at a community garden in Khayelitsha, Cape Town, along with several other potential winter rainfall crops.
It is recorded as having been foraged historically, though there is little evidence of it still being eaten as a leafy green vegetable in a traditional way.
There is however a growing group of chefs, food innovators, foragers, gardeners, community farmers and local knowledge holders who are re-kindling an interest in the culinary use of Cape wild food plants. Though current access to ingredients is mostly limited to foraging – plants growing in the wild or in urban environments – there is interest in developing a culture of cultivation.
The leaves are best picked in the rainy season, when they are young, plump and tender, harvesting an appropriate length of runner. The individual leaves which get plucked off the stems which might have become a bit woody, can be used much as you would ordinary or New Zealand spinach (Tetragonia tetragonoides), to which it is related, It is used both raw as well as cooked, in salads, stir-fries, pie fillings, stews or soups as well as in tempura. The leaves preserve well in oil or vinegar pickles and ferments.
There has been some experimentation to capture the delicate honey-like fragrance of the flowers in a vermouth and in a cordial.