Comparative structure of the osmophores in the flowers of Stanhopea graveolens Lindley and Cycnoches chlorochilon Klotzsch (Orchidaceae)

Abstract

The genus Tradescantia comprises about 70 species. In Poland Tradescantia x andersoniana is basically grown as an ornamental plant that is recommended for borders and to be planted around garden ponds. The present study investigated flowering as well as the micromorphological and anatomical features of some floral elements of Tradescantia x andersoniana W. Ludw. Rohweder 'Karin'. The macro- and micromorphology of the flowers was examined using stereoscopic, light, and scanning electron microscopy (SEM). Spiderwort produces flowers with a diameter of 4.6-5 cm, which open early in the morning and close at noon. Non-glandular and glandular hairs grow on the abaxial surface of the calyx and on the apical part of the ovary. The glandular hairs develop a several-celled stalk and a unicellular spherical or elongated head. The staminal filaments produce chain-shaped trichomes. Striate cuticular ornamentation is found on their surface and on the epidermis covering the perianth. The striae on the cells of the stamen hairs run to the two poles of the cell. The pistil develops a wet stigma with unfused unicellular papillae. The cuticle on their surface is smooth, whereas on the style near the stigma it forms dense folds.