Exploring the world of edible aroids
AROIDS are plants from the family Araceae such as anthurium, elephant’s ear plant, and dumb cane. The leaves and tubers of many aroids contain exceedingly sharp minute crystals of calcium oxalate.
These crystals can puncture the delicate skin of the mouth and tongue, causing irritation. Thus farmers keep animals such as cattle away from these plants.
Yet there are aroid plants and tubers that can be consumed. However, the outer tuber skin should be removed and the aroids must be cooked well. Note that wild aroids could contain cyanogenetic glucosides that may contain toxic levels of prussic acid, hence thorough cooking is needed. Some aroids chosen for cultivation have nearly no crystals or very low levels of them, but they still require cooking. The juice of aroids will stain material indelibly. Taro (Colocasia esculenta) The taro is usually confused locally with the yam (Dioscoreaceae), which is actually a vine. Taro has a superior flavour and texture to yam, and is popular in the Pacific and tropical Asia. Here there are at least 200 varieties of taro, which is sometimes referred to as the ‘potato of the tropics’.
Geoffrey Herklots wrote in ‘Vegetables in South East Asia’ (1972) that this crop has been cultivated since the Han Dynasty, around 206 BC. Taro was the staple food of the early dwellers in Asia and the Pacific islands such as the Solomon Islands, Vanuatu, New Caledonia, and Fiji.
A favourite taro is the Colocasia esculenta antiquorum, which is getting very expensive now. It is native to India and likely other parts of Asia, where it is widely cultivated. The bulging starchy corms can be roasted, fried, boiled, or mashed.
The flesh of the tuber may be white, creamy, or tinted with yellow, magenta or purple. These colours may remain in the cooked flesh. Care must be taken to ensure the cooking process is long enough to destroy the calcium oxalate crystals. In addition to the tubers, the leaves, leaf stalks, and etiolate of the shoots may be eaten too.
The tubers can also be used as a source of starch for fermentation to make alcohol.
Giant swamp taro (Cyrtosperma merkusii)
This is a taro found on the islands of Micronesia and Polynesia. About 10 species occur widely in the tropics, and it is a staple food for many in the Philippines. The plant grows very large and has the rare merit of growing well on coral atolls. It can be planted in freshwater beds with mud at the bottom and filled with humus.
In the Solomon Islands, the rhizomes are harvested earlier for food.
Tannia (Xanthosoma sagittifolium)
Tannia comprises several species well known in the West Indies. Some were introduced to New Caledonia and Papua New Guinea. Its large rhizome is normally used for fodder feed. It has similar properties to taro, yam and sweet potato. Cultivation Cultivation is mainly by vegetative means such as seeds. In the propagation of eddoes, both the tops and lateral corms are used.
The tops refer to part of the vegetative old corm, where the buds and roots under soil level are also used for replanting. It is best planted just before the rainy season and would take eight months before harvest, when the leaves will turn yellow. In Fuzhou, China, I saw farmers growing aroids along the edges of the dykes and bunds of rice paddies.
Taro grows in soil that is too wet for sweet potatoes, so it needs heavy rainfall during its growth period and continuous high soil water content. Harvested taro cannot be stored for long periods but when left in the field, they can last for a very long period.
We should have a greater appreciation of edible aroids as they could be a very valuable food source as the world’s population continues to grow.
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Happy gardening.