What do some seeds and fruits have that allows them to float?

Some fruits and seeds have specialized structures that assist them in floating and aiding their dispersal over water. These adaptations enhance their ability to colonize new habitats and expand their geographic reach. Two well-known structures that enable floating are:

1. Air Pockets: Certain seeds and fruits possess internal air pockets or sacs filled with air. These pockets reduce the overall density of the seed or fruit, allowing it to float on the water's surface. Examples of plants that utilize air pockets for buoyancy include coconuts (Cocos nucifera) and dried pods of the water hyacinth (Eichhornia crassipes).

2. Specialized Tissues: Other plants have evolved lightweight tissues that play a role in floating. These tissues are typically composed of cells with large intercellular spaces that trap air and decrease overall density. The spongy mesocarp of water lilies (Nymphaea spp.), for instance, contains air-filled chambers that aid in buoyancy and assist the plant in floating on the water.

These floating adaptations are instrumental in the dispersal of plants across bodies of water, allowing them to travel long distances and colonize new environments. Currents, waves, and water flow can carry these buoyant fruits and seeds to suitable habitats, promoting their establishment and genetic diversity in various ecosystems.