A 2013 linear sequence of legume genera set in a phylogenetic context - A tool for collections management and taxon sampling

The Leguminosae (or Fabaceae) currently comprises 751 genera. In most of the world's herbaria the genera are arranged by old, non-phylogenetic, classification systems which, while offering insights into morphological similarity, make no explicit statement as to evolutionary relationships. While classifications based on morphology are useful tools for plant identification, they do not offer the predictive value that phylogenetically based linear sequences provide. The legume collection of c.750,000 specimens in the Herbarium of the Royal Botanic Gardens, Kew was moved to a new building between 2010 and 2011, which presented the opportunity to reorganise the collection by a linear sequence based on a number of relatively comprehensive published legume phylogenies. The numbered linear sequence adopted at Kew has been updated and emended to include generic changes that have been published up to March 2013. The linear sequence, together with an alphabetical list of genera, is presented here to serve as a management tool for future taxon sampling and herbarium curation. The process used to develop the linear sequence and to rearrange the legume collection at Kew is discussed together with plans for future dissemination of changes to the sequence as new phylogenies are published and incorporated.