The largest plant seed in the world belongs to the Double Coconut Palm or coco-de-mer (Lodoicea maldivica), which tips the scales at a whopping 30kg. This plant also has some of the longest leaves and its tall stock can grow upwards of 34 metres in hight. The double coconut palm grows naturally on the Praslin and Curieuse Islands and is now extinct on St Pierre, Chauve-Souris and Round Islands. This plant is listed as vulnerable, the biggest threat? Those wonderful seeds which people love to collect. When people pick up these seeds it prevents the plant from growing new palms.