Pollen Morphology and Palynological Diversity of Selected Ornamental Climbers

Palynological studies play a vital role in plant taxonomy, systematics, and evolutionary research by providing diagnostic characters of pollen grains. The present investigation examines the pollen morphology of twelve ornamental flowering plant species belonging to ten families, namely Nyctaginaceae, Solanaceae, Ranunculaceae, Lamiaceae, Combretaceae, Convolvulaceae, Oleaceae, Bignoniaceae, Passifloraceae, and Acanthaceae. Pollen grains were analyzed for size, shape, aperture type, and exine ornamentation using standard palynological techniques. Pollen size varied considerably, ranging from 8 µm in Ipomoea purpurea to 63 µm in Ipomoea quamoclit and Thunbergia grandiflora. The pollen grains exhibited diverse shapes, including spheroidal, prolate, prolate-spheroidal, oblate-spheroidal, and sub-spheroidal forms. Aperture types included pantoporate, tricolpate, tricolporate, and syncolpate, while exine ornamentation varied from granulate-spinulose and echinate to finely reticulate and reticulate patterns. Reticulate ornamentation was the most frequently observed exine type among the studied taxa. Distinct variations in pollen morphology among species and families demonstrate the taxonomic significance of palynological characters. The findings highlight the usefulness of pollen morphological features in species identification, systematic classification, and comparative studies of ornamental angiosperms, contributing valuable baseline information for future palynological, taxonomic, and biodiversity research.