The paper presents in the first time the results of a micromorphological study on stamens of Sansevieria species. Flowers of 15 species obtained from herbarium specimens deposited at the Royal Botanic Gardens, Kew, the Botanical Garden Berlin-Dahlem and the Botanical Garden in Poznań were studied. Observations were conducted under a light and a scanning electron microscope. The study revealed significant differences between the outer and inner surfaces of anthers. All species have a well-defined endothecium of enlarged cells with a U-shaped or helical secondary wall thickening. The article includes descriptions and illustrations of several quantitative and qualitative features of anthers and filaments of some Sansevieria species. Our study indicates that stamen micromorphology may be taxonomically significant.
The present study involved the measurement of size and the micromorphology of the floral elements of Anchusa officinalis L. which are attractants for insects. The structure of the epidermis on the surface of the calyx, petals, throat scales, pistil and nectary were analysed using light and scanning electron microscopy (SEM). For light microscopy observations, semi-permanent slides were prepared, which were treated with Lugol’s iodine solution, Sudan III and fluoroglucine. The dark violet lobes of the corolla of Anchusa officinalis, with a velvety surface, and the throat scales, contrasting with them, belong to the most important optical attractants which lure insects from large distances. The dark pink colouring of the sepals additionally increases the attractiveness of the flowers. The epidermis covering the calyx formed different-sized non-glandular trichomes as well as glandular trichomes. The glandular trichomes were composed of a uni – or bicellular leg and a unicellular head. The colour of the corolla petals was determined by anthocyanins accumulated in the epidermal cells and in the more deeply situated parenchyma. The velvety surface was formed by the conical papillae, densely growing from the adaxial epidermis. The pink-violet throat scales with white hairs, covering the inlet to the tube of the corolla, were found at the inlet to the corolla throat. The longest trichomes on the surface of the scales were located in their lower and middle parts, whereas the shortest ones at their tips. The epidermis of the central part of the throat scales formed small papillae. The trichomes had thin cell walls, large vacuoles, numerous plastids and lipid droplets. The two-parted stigma of the pistil was covered by characteristic expanded outgrowths with wavy edges which performed the functions of structures facilitating the capture of pollen grains. As a result of the present study it was found that the structures affecting the attractiveness of the flowers, through various light effects within the corolla of Anchusa officinalis, include the papillae on the corolla surface, trichomes of the throat scales and the epidermal cells of the style. The trichomes of the scales can also be responsible for protecting pollen and nectar against rainfall.
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.
The morphology and anatomy of generative organs of Salsola kali ssp. ruthenica was examined in detail using the light (LM) and scanning electron microscopy (SEM). The whole flowers, fruits and their parts (pistil, stamens, sepals, embryo, seed) were observed in different developmental stages. In the first stage (June), flower buds were closed. In the second stage (August), flowers were ready for pollination/fertilization. In the third stage (September), fruits were mature. Additionally, the anatomical and morphological structure of sepals was observed by means of LM and SEM. Thanks to the transverse and longitudinal semi-sections through sepals, the first phase of wing formation was recorded by SEM. The appearance of stomata in the epidermal cells of sepals above the forming wings was very interesting, too. The stomata were observed also in mature fruits.
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