Yam plants have thick tubers (generally a development of the base of the stem), from which protrude long, slender, annual, climbing stems. The leaves are either alternate or opposite and can be entire or lobed. The unisexual flowers are borne in long clusters. The flowers are generally small and individually inconspicuous though collectively showy. Yam flesh ranges in colour from white to yellow, pink, or purple and varies in taste from sweet to bitter to tasteless