"Sword Plants" came from the Echinodorus genus and are marsh or bog plants from the tropical western hemisphere (North, South and Central America as well as some islands in the area). While there are around 3 scientifically accepted species, many species are cross-bred and propagated by hobbyists and nurseries to create numerous variants and hybrids.
While swords may grow emerged in the wild (with their leaves out of the water), they are well tailored to submerged life inside the aquarium as nicely. Emerged plants grow flowers, while submerged plants will reproduce by sending out runners to grow new plants. Most swords require high lighting to thrive. In , they also benefit from a nutrient-rich substrate and iron and CO2 supplements, especially in heavily planted aquariums.