A seed, in botanical terms, is a protective package for a plant embryo, containing stored nutrients and encased in a seed coat. These structures represent the reproductive unit of seed plants, allowing them to disperse and survive for periods of dormancy until conditions are favorable for growth. The plant kingdom exhibits a wide range in seed size, from microscopic dust-like particles to large specimens. This diversity reflects various evolutionary strategies for survival and propagation across different environments.
The Coco de Mer: Holder of the Record
The Coco de Mer (Lodoicea maldivica) holds the record for the world’s largest seed. This rare palm tree is found exclusively on two islands in the Seychelles archipelago: Praslin and Curieuse, located in the Indian Ocean. Its enormous seed can measure up to 50 centimeters (20 inches) long and weigh as much as 25 kilograms (55 pounds), though some have reached 30 kilograms (66 pounds). The seed’s unique bilobed shape often resembles a female pelvis, contributing to its “love nut” or “double coconut” nicknames.
The Coco de Mer palm is a towering species, reaching heights of up to 30 meters (100 feet). The development of its fruit, which contains the massive seed, takes a long time, 6 to 7 years to ripen on the tree. After falling, the seed can take two more years to germinate, and the tree grows slowly, requiring 25 to 30 years to reach maturity and begin producing its own seeds. Some Coco de Mer palms are estimated to live for hundreds of years, up to 350 years.
Due to its limited natural distribution and historical overexploitation, the Coco de Mer is listed as endangered. The trade of its seeds is strictly controlled by Seychellois law to protect wild populations. This plant also holds cultural significance, with parts of the tree historically used by locals for ropes and roofing.
Why Seeds Grow So Large
Large seeds provide advantages for a plant’s offspring, particularly in challenging environments. They contain substantial energy reserves as stored nutrients, essential for the embryo during germination and early seedling development. This food supply allows seedlings to establish themselves robustly, increasing their survival rates, especially in nutrient-poor soils or under competitive conditions.
In dense, shady environments, a large seed can provide the initial energy needed for a seedling to grow quickly and reach sunlight. This is a trade-off: producing fewer, larger seeds means less dispersal, but each seed has a higher chance of establishment. Large seeds prioritize the vigor and competitive edge of the individual seedling. The Coco de Mer’s seeds, for instance, are too heavy to float, suggesting their size is not for widespread oceanic dispersal but for giving the seedling a strong start in its localized, competitive forest habitat.
Other Notable Giant Seeds
While the Coco de Mer holds the record, other plants also produce large seeds, each adapted to its environment and dispersal mechanism. The coconut (Cocos nucifera) is another well-known example of a large seed, though botanically it is a fibrous one-seeded fruit. The coconut’s outer layers make up a fibrous husk that provides buoyancy, allowing the “seednut” to be dispersed across oceans by water currents. Its large size also provides stored energy for germination in new locations.
Another familiar large seed is the avocado pit. While not as massive as the Coco de Mer or coconut, the avocado seed is considerable relative to the fruit’s flesh. The avocado seed’s size is thought to be an evolutionary anachronism, having co-evolved with now-extinct megafauna that dispersed seeds through their digestive systems. These examples demonstrate the diverse strategies plants employ, where seed size is an adaptation for survival and propagation.