Since flower arrangement (Chinese: 插花; pinyin: chāhuā) arrived in Japan from China together with Buddhism, it was naturally imbued with Chinese and Buddhist philosophy. The Buddhist desire to preserve life lies at the root of much of ikebana practice, and has created most of the rules of flower arrangement, controlling also the shapes of the flower vases, formed as to help to prolong the life of the flowers.[22] Consideration of the vase as being something more than a mere holder of the flowers is also an important consideration. The surface of the water is always exposed, alongside the surface of the earth from which the grouping of flowers springs. This aids in creating the effect of representing a complete plant growing as nearly as possible in its natural conditions.Wikipedia