From Naruto wikia:
Kekkei genkai (血継限界; Literally meaning "a technique limited to inheritance by blood" or "Bloodline Limit") are abilities passed down genetically in specific clans. It's possible for a ninja to have more than one of these abilities. Kekkei genkai abilities that work via the user's eye are called dōjutsu. Other kekkei genkai include mixing one type of elemental chakra with another, creating a new one unique to the users, which is usually impossible for normal ninja
Wood Release (Mokuton) (木遁, Mokuton; English TV "Wood Style") is an advanced nature kekkei genkai that combines earth and water-based chakra natures to create wood or complete trees. This ability can also be used to create flowering trees.[1] Wood Release techniques can be produced from anywhere, including the user's body, as the user's chakra is literally converted into a source of life.