In dicot leaves, stomata are generally present on lower epidermis (hypostomatic), whereas in monocot leaves, they are present on both the surfaces (amphistomatic). In freefloating hydrophytes, stomata are restricted to upper epidermis (epistomatic) whereas in submerged hydrophytes, stomata are either non-functional or absent. In algae and fungi, stomata are totally absent. Stomata are sunken (deep seated) in case of xerophytes.