The largest seed in the world is the seed of the Coco de Mer, also known as the Lodoicea.
The mature fruit is usually 40 - 50 cm (15.7 - 19.6 inches) in diameter and usually weighs 15 - 30 kg (33 - 66 pounds), and contains the largest seed in the plant kingdom, which also makes it the largest nut in the world.
It produces the largest wild fruit so far recorded, weighing up to 42 kg, the mature seeds weighing up to 17.6 kg are also the world's heaviest.
The fruit, which requires 6 - 7 years to mature and a further two years to germinate, is sometimes also referred to as the sea coconut, love nut, double coconut, coco fesse, or Seychelles nut.
The fruit is used in Siddha medicine, Ayurvedic medicine and also in traditional Chinese medicine. In food, it is typically found as flavor enhancers for soups in southern Chinese cuisine, namely cuisine around the Canton country
The shape is very apt...
Further Info: https://en.wikipedia.org/wiki/Lodoicea