P. malgassicum anther A Semithin section stained with toluidine blue showing the shape and structure of the anther. Anther wall (here already dehiscent) formed by 2–3 layers of cells B semithin section showing the microspores surrounded by the tapetum C microspores are in the locule surrounded by the tapetum. Small electron-dense particles (orbicles) are lined along the tapetal cells plasma membrane, while some larger masses can be observed in the locule (black arrow) D anther trichome. Some plastids contain large electron-dense bodies E detail of D The large electron-dense bodies inside the plastid occur together with starch grains F anther epidermis: electron-dense bodies are present in the vacuoles. Some plastids are present with stored starch. Large medium electron dense granular bodies can be found between the vacuole and the external plasma membrane G in a preliminary stage, the electron-dense masses in the vacuole are surrounded by a more electron transparent layer H at a successive stage, the electron-dense bodies occupy a large part of the vacuolar volume. Ga: microspores/male gametophyte; L: locule; sp: tapetum/sporophytic tissue; ep: epidermis; end: endothecium, ml: middle layer; st: secretory tapetum; Mcs: microspore; EDB: electron-dense bodies; Mt: mitochondria; Pa: protein aggregate; Ep: elaioplast; yLPT: young lipotubule: Lpt: lipotubule; V: vacuole; Td: terpenic droplets.