Influence of stomatal traits on the ecological classification of selected plants in the lateritic belt

Stomatal morphology and distribution exhibit remarkable diversity across monocot and dicot species, reflecting their evolutionary adaptations to varied ecological niches. This study investigates the stomatal diversity in selected taxa, highlighting its taxonomic significance and functional implications. In monocots, the presence of brachyparacytic stomata in Acorus calamus represents a primitive trait, while the tetracytic condition in Kaempferia galanga and Tradescantia spathacea suggests advanced gas exchange mechanisms. Hypostomatic species like Costus speciosus and Tradescantia spathacea indicate adaptations for water conservation, whereas amphistomatic taxa such as Acorus calamus, Caladium bicolour, Dracaena marginata, and Kaempferia galanga thrive in humid environments. Dracaena marginata and Polianthes tuberosa exhibit anomocytic stomata, linking them to basal monocot lineages. The unique dumbbell-shaped guard cells of Cynodon dactylon exemplify Poaceae’s optimization of transpiration control.

Dicot species exhibit a spectrum of stomatal adaptations aligned with their ecological conditions. Bryophyllum calycinum demonstrates anisocytic stomata along with CAM metabolism, enhancing water-use efficiency. Calotropis procera displays diverse stomatal types, suggesting specialized xeric adaptations. Anomocytic stomata in Euphorbia neriifolia, Rauwolfia serpentina, and Tabernaemontana divaricata indicate a basal evolutionary trait balancing transpiration. Hypostomatic conditions in Ficus microcarpa and Rauwolfia serpentina promote water conservation, while sunken stomata in Nerium oleander and Ficus microcarpa reduce transpiration.

Additionally, stomatal multiplicity in both dicots and monocots were observed. Novel types, including laterocytic, stephanocytic, diacytic, cyclocytic, amphipseudoholoparacytic, stomata were also reported. Scanning electron microscopy revealed sunken stomata and non-contiguous stomatal clusters. These findings underscore the interplay of genetic and environmental factors in stomatal development. Further molecular and physiological studies will help us to understand how stomatal diversity evolved and adapted. This will improve our knowledge of plant responses to climate change and water-use efficiency.