Evolution of Stilbocarpa, a megaherb from New Zealand's sub‐antarctic islands

Abstract

Challenges to the traditional circumscription of Apiaceae and Araliaceae are emerging as a result of phylogenetic analysis of DNA sequences. Traditionally classified as Araliaceae, Stilbocarpa emerges with Schizeilema and Azorella, both members of the Apiaceae. In our analyses of nuclear ITS sequences, these three genera comprise a distinct Southern Hemisphere lineage. The humid climate, cool equable temperatures, locally abundant nutrients, and absence of herbivores are ecological features of the sub‐antarctic islands that may have contributed to the evolution of the unusual megaherb, Stilbocarpa, from these diminutive apiaceous ancestors.

Keywords:

• Apiaceae
• Araliaceae
• megaherb
• phylogenetic relationship
• Stilbocarpa
• sub‐antarctic islands