A yam is any of several plant species of the genus Dioscorea (family Dioscoreaceae),
native to warmer regions of both hemispheres. A number of species are cultivated
for food in the tropics; in certain tropical cultures, notably of West Africa
and New Guinea, the yam is the primary agricultural commodity and the focal point
of elaborate ritual.
Yams have thick tubers (generally a development of the base of the stem),
from which protrude long, slender, annual, climbing stems bearing leaves, which
are either alternate or opposite and either entire or lobed and unisexual flowers
in long clusters. The flowers are generally small and individually inconspicuous,
though collectively showy. Each consists of a greenish, bell-shaped or flat
perianth of six pieces, enclosing six or fewer stamens in the male flowers
and surmounting a three-celled, three-winged ovary in the female flowers. The
ovary ripens into a membranous capsule, bursting by three valves to liberate
numerous flattish or globose seeds.
Most yams contain an acrid principle that is dissipated in cooking. D. trifida
and D. alata are the edible species most widely diffused in tropical and subtropical
countries. The tubers of D. alata sometimes weigh 45 kg (100 pounds). D rotundata
and D. cayenensis are the main yam species grown in West Africa. D. esculenta,
grown on the subcontinent of India, in southern Vietnam, and in the South Pacific
islands, is one of the tastiest yams. D. batatas, the Chinese yam, or cinnamon
vine, is widely cultivated in East Asia.
Hundreds of species of yams are known, and they vary widely in taste and appearance.
Yams' flesh ranges in colour from white to yellow, pink, or purple. They vary
in taste from sweet to bitter to tasteless. Yams are consumed as cooked starchy
vegetables. They are often boiled and then mashed into a sticky paste or dough,
but they may also be fried, roasted, or baked in the manner of potatoes.
Fufu
The preparation of fufu is a communal ritual; a hard, laborious
task done by women. First yams are washed, peeled, cut up and boiled until
soft. Then
two or three women pound the cooked yams in a pestle with thick sticks until
the yam has the consistency of baker’s dough. The noise the fufu pounders
make is one of the most instantly recognisable sounds in Togo. Like pâtes,
fufu is eaten with sauces. Groundnut, goat and palm nut are popular flavours.