Sophora (Fabaceae) in New Zealand: Taxonomy, distribution, and biogeography

Abstract

A taxonomic treatment is provided for the Sophora microphylla complex in New Zealand. Sophora microphyllu sens. str. is endemic to New Zealand, and includes those plants with a distinct divaricating and/or strongly flexuose juvenile Phase, orange‐brown to Yellow‐brown Juvenile stems, and distant leaflets. S. chathamica is reinstated at species rank, S.fulvida is a new combination provided for the taxon previously known as S. microphylla Var. fulvida, and S. godleyi and S. molloyi are described as new species. S. chathamica, S. fulvida, S. godleyi and S. molloyi lack a divaricating and/or strongly flexuose juvenile phase and are each distinguished by a number of leaf characters. S. fulvida and S. godleyi have distinctive leaf hairs. S. chathamica is a predominantly coastal species in Northland, Auckland, Waikato, Wellington, and the Chatham Islands, S.fulvida occurs in Northland and North Auckland on volcanic rock outcrops S. godleyi Occurs on calcareous mudstone and sandstone in eastem Taranaki King country, Wanganui and Manawatu, and S. molloyi is restricted to extremely dry and exposed bluffs and rock outcrops of southern North Island headlands, Kapiti Island, and several islands in Cook Strait. Cluster analyses of 11 leaf and 4 growth habit characters provide additional support for the revised classification, and variation in 7 leaf characters is evaluated with box plots. A key is provided to Sophora in New Zealand, hybridism is discussed, an assessment of each species’ conservation status is made, and biogeography is reconsidered in view of the new taxonomic treatment.