Root cap is absent in
Root cap is present at the tip of the root and it contains meristematic cells which divide and increase the length of the root.
Mesophytes are terrestrial plants. Therefore, root cap is essential in mesophytic plants.
Epiphytes are plant which grows upon another plant or any object. They require physical support for the growth. Such plants also possess roots which anchor the plant to another plant or object.
Xerophytes are terrestrial plants which have adapted to survive in an environment with little water. Hence, roots are necessary for xerophytes.
Hydrophytes grow in water. The root system in hydrophytes need not penetrate the soil particles to reach water and hence the root tips do not face abrasive forces or friction. The root caps in terrestrial plants are protective in function. Therefore, root cap is absent in hydrophytes.
Therefore, the correct answer is 'Hydrophyte'.