People often call the knight star ‘Amaryllis’, but that is actually a misnomer. The real Amaryllis has massive stalks, usually with pink flowers. This plant, however, has hollow flower stalks, often with red and white flowers, although you can sometimes get them in purple, pink or salmon pink colours.
The name Hippeastrum comes from the Greek and literally means ‘knight’s star’, referring to the star-shaped petals. Hippeus = knight and astron = star.