Egeria densa, formerly known as Elodea densa and often referred to as 'Elodea' or simply 'pondweed'. Egeria densa is an excellent substitute for Elodea Crispa which is no longer permitted in the UK.
Elodea can be used as a live model to observe chloroplasts in motion (cytoplasmic streaming) inside of the cytoplasm. Elodea leaves are only 2 cells thick and unlike other plants, its epithelial cells carry out photosynthesis. Experiment features in OCR GCSE Biology curriculum (PAG B6, PAG B7).
Do not release into ponds or rivers as Egeria densa can be invasive.