Crystal orchid. Crystal orchid, also known as dream orchid, Chinese milk vetch, silver key, purple ghost and so on. Crystal orchid is a flower that grows on rotten leaves. This flower is crystal clear all over. Known as the flower of the underworld, dream orchid. The novel is called ghost flower, which is a deadly poison. This kind of flower usually appears white at night, which looks scary and is a kind of flower to attract ghosts.