The Coco de Mer tree grows to 25–34 m tall. The leaves are fan-shaped, 7–10 m long and 4.5 m wide with a 4 m petiole. It is dioecious, with separate male and female plants. The male flowers are catkin-like, up to 1 m long. The mature fruit is 40–50 cm in diameter and weighs 15–30 kg, and contains the largest seed in the plant kingdom. 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, Bum Seed, double coconut, coco fesse, or Seychelles Nut.