The lotus seed is the pale, rounded kernel of the sacred lotus, Nelumbo nucifera, an aquatic perennial whose pink-white flowers give way to a distinctive flat-topped seed-head shaped like a watering-can rose, each pod cradling a dozen or more seeds in its own little socket. Fresh from the pod the seed is crisp, juicy and faintly sweet, like a soft green nut; dried and cooked it turns starchy and floury with a delicate chestnut-like bite and a mild, earthy, nutty taste. It is one of the most versatile seeds in East and South Asian cooking — eaten raw as a snack, simmered into soups and tong sui, and sweetened into the smooth golden paste at the heart of the mooncake.