Poppy ovary with developing seeds. Light micrograph (LM) of a cross-section through the centre of a mature poppy ovary, showing placentas bearing developing seeds (red). Each placenta has an epidermis layer (purple), that bears the ovules (female sex cells). In this case they have been fertilised by male sex cells in pollen grains and are developing into seeds. Also seen are nuclei (red dots) and chloroplasts (green), which contain the green pigment chlorophyll used by the plant for photosynthesis.