They float because of the presense of Aerenchyma( a parenchyma tissue which provides buoyancy

Explanation:

Introduction:
The lotus plant is known for its ability to float on the water surface. This unique characteristic is due to various adaptations and structural features that allow the lotus to stay afloat.

Adaptations and Structural Features:

Air-filled Spaces:
The lotus plant has air-filled spaces in its stem, leaves, and flowers. These spaces provide buoyancy to the plant, allowing it to float on the water surface. The air-filled spaces also make the plant light and help it maintain stability.

Water-repellent Surface:
The leaves and flowers of the lotus plant have a waxy coating that repels water. This hydrophobic surface prevents water from being absorbed into the plant, enabling it to float effortlessly on the water surface. The water-repellent surface also helps protect the plant from becoming waterlogged and sinking.

Large Air Spaces in the Leaf Petioles:
Lotus leaves have long, hollow petioles that contain large air spaces. These air-filled spaces contribute to the buoyancy of the plant, keeping it afloat. The large air spaces also provide structural support to the leaves, allowing them to stay above the water surface.

Flexible Stem:
The stem of the lotus plant is flexible, which enables it to adapt to changes in water level. As the water level rises or falls, the stem bends accordingly, allowing the plant to maintain contact with the water surface. The flexible stem helps the lotus plant adjust to different water conditions and ensures its ability to float.

Conclusion:
The lotus plant is able to float on the water surface due to its various adaptations and structural features. The air-filled spaces in its stem, leaves, and flowers provide buoyancy, while the water-repellent surface prevents water absorption. The large air spaces in the leaf petioles and the flexible stem further contribute to the plant's ability to float. These adaptations allow the lotus plant to thrive in its aquatic habitat and showcase its remarkable floating ability.