Abstract
Various morphological components of Millingtonia hortensis Linn. f. (cultivated in Dubai as road-side ornament) were studied for their surface micromorphology. The surface of this plant presented three important structures – much distributed trichomes on the surface of all organs of this plant, stomata present on leaf, pedicel, petals and fruit and tracheoidal system making the wing surface. The leaf was characterized with peculiar cuticular striation running parallel to each other and occasionally twined as the rope. Striations were generally confined within the perimeter of an epidermal cell but sometimes passing over several cells. Thirteen types of glandular and non-glandular trichomes are described in toto in this study – many of which were already described from this species but some of the trichomes were probably not observed in earlier studies e.g., 1) Branched moniliform trichomes on petals imparting velvet touch to the petal, 2) Multicellular uniseriate conical and stiff NGT with curved apical cell on peduncle, 3) Unicellular soft non-glandular trichome on petal, 4) Glandular trichomes present in pit and attached laterally with epidermis of the leaf and 5) Club shaped glandular trichomes on pedicel. Stomata were anomocytic type, raised above epidermis and with well-defined rim around. Guard cells outer ledges were very prominent. Contiguous stomata were frequent. Occasionally, triplet stomata were also present. Seed wing was thin and papery and composed of tracheoids running all over the seed surface in a fan like manner. Seed wing was porous with air spaces of varying sizes, well-suited for dispersal of seeds. The large air spaces showed tracheoidal ingrowths forming knotlike structures of various shapes and sizes, possibly for mechanical support to the wing. The findings are discussed in the light of available literature
