Shoot flammability of vascular plants is phylogenetically conserved and related to habitat fire-proneness and growth form.

Terrestrial plants and fire have interacted for at least 420 million years. Whether recurrent fire drives plants to evolve higher flammability and what the evolutionary pattern of plant flammability is remain unclear. Here, we show that phylogeny, the susceptibility of a habitat to have recurrent fires (that is, fire-proneness) and growth form are important predictors of the shoot flammability of 194 indigenous and introduced vascular plant species (Tracheophyta) from New Zealand.