Classification, origins, and patterns of diversification in New Zealand Carmichaelinae (Fabaceae)

Analysis of ITS sequences provides support for a clade that includes Carmichaelia, Clianthus, Montigena, and Swainsona. We provide a node-based definition and recommend that this clade be called Carmichaelinae. Results suggest that Carmichaelinae are derived from northern hemisphere Astragalinae. The clade has extensively radiated in Australia, and two independent lineages have diversified in New Zealand. The New Zealand lineages differ in species richness. One lineage consists of 24 species placed in Carmichaelia and Clianthus, while the other corresponds to the monotypic genus Montigena. The pattern of relationships inferred from ITS sequences suggests that the New Zealand radiation was recent and possibly accompanied episodes of mountain-building and glaciation.