Adaptations are many and varied. Many aquatic flowing plants have leaves that lie flat on the water for maximum sunlight collection. The stems of many aquatic plant have large air-filled areas to increase buoyancy. Many fruits of aquatic plants float on water, which increases dispersal as fruits and seeds float away. Plants like cattails or reeds however may hold their fruits high above the water for wind dispersal. Many aquatic plants have deep, anchoring roots, but some, like duckweeds float freely and allow their roots to drift in the water below them. One aquatic plant is eel grass, which has adaptation for living in salt water.