Hydrophytes are plants, such as water Hyacinth and water lily, that live in fresh water. All or part of their body is in water. In these plants, the cuticle of the immersed body parts Is thin and allows water to enter freely over the whole body surface. As a result, special water absorbing and water conducting structured are not important. In addition, since they are surrounded by water, they do not need much mechanical support like land plants. Hence , in Hydrophytes,
• the roots (water absorbing) and
• vascular xylem or wood (water conducting and mechanical) is poorly developed.
Water contains less oxygen than air. Most aquatic plants, therefore, have large, well developed air spaces. These not only provides a supply of oxygen to the underwater parts of the plant but also make the plant buoyant and so help it to float.
Note. The floating parts of Hydrophytes that are exposed to air are covered with a thick cuticle to prevent water loss.
