Not all plants photosynthesize

Although we're taught in school that the trademark of a plant is their ability to photosynthesize, that's not always the case, with several species having lost their ability to photosynthesize. Instead, such plants often parasitize other plants, stealing their nutrients, as as is the case for the important crop weed, Striga. In other cases the plant may parasitize fungi that live in the soil, as is the case for many orchid species.