Tree Definitions for the National Big Tree Program

  • Cultivar – A cultivar is a plant derived from of assemblage of plants that has been selected for desirable characteristics that can be maintained by propagation.
  • Hybrid - A hybrid is the offspring of plants resulting from interbreeding between two different taxa, or group, of one or more populations of organisms. Hybrids may be of human origin or may naturally occur in the wild and may be the result of crosses between native species, native and non-native species, or non-native species.
  • Invasive - An invasive tree species is a non-native plant that is able to spread widely and quickly into a variety of ecosystems and often displaces native species, thereby disrupting ecosystem function.
  • Native (indigenous) – A native tree is one that occurs naturally in an area that was not introduced intentionally or unintentionally by human activity.
  • Naturalized: A naturalized tree is a non-native species that has become common in unmanaged areas and is able to reproduce and maintain itself without human assistance.
  • Non-native (non-indigenous) – A non-native tree is one that occurs in an area that was introduced intentionally or unintentionally by human activity.
  • Ornamental - An ornamental tree is a species that is grown for aesthetic or decorative purposes.
  • Variety – A variety is the taxonomic subdivision of a plant species that naturally replicates the same unique characteristics of the parent tree in a relatively minor way.