Megaherb

thumb|upright=1.6|Megaherbs on Campbell Island Megaherbs are a group of herbaceous wildflowers growing in the New Zealand Subantarctic Islands and on the other subantarctic islands. They are characterised by their great size, with huge leaves and very large and often unusually coloured flowers, which have evolved as an adaptation to the harsh weather conditions on the islands. They suffer from overgrazing due to introduced mammals.

== Appearance and occurrence == thumb|upright=1.6|Close-up on megaherbs on Enderby Island Originally, the term was coined to describe large-leaved herbs that form meadows in the subantarctic islands but has also been applied to describe tropical alpine vegetation forms found in the Andes, East Africa and New Guinea. They are large herbs that can reach dimensions of over , often feature strikingly colourful flowers, large leaves and long stalks, and are important components of the ecosystems of the subantarctic islands. Beyond these traits, megaherbs can have different forms; for example, some genera have perennial leaves and others are deciduous. Intensely coloured flowers are not unique to megaherbs but also occur on other plant species in the same environments and either arose by chance or are evolutionary adaptations to the environment.