The term 'life-form' refers to the general habitus and morphology of a plant. It is predominantly determined by the plant's blueprint but can - to some extent - be modified by the environment. Multiple classification systems have been developed regarding this character. Most reliable and often used is the system of Raunkiaer which is based on the location of perennating organs (perennating buds): chamaephyte, geophyte, hemicryptophyte, hydrophyte, phanerophyte, therophyte.