Abstract

Phylogenetic affinities among Chilean Sophora species are not clear. We suggest a new hypothesis for the origin of the section Edwardsia on the basis of parsimony analysis, which allows a South American origin to be established for the species of this section. The seed alkaloid composition did not provide useful information for the filiation of Edwardsia species, and the shortest tree was obtained using morphological characters only. Two branches are clearly distinguishable by the pubescence of the leaflets and the flag/wings length ratio: one of them includes S. chrysophylla, S. tetraptera, S. toromiro, S. howinsula and S. denudata; the other one includes S. macnabiana, S. microphylla, S. masafuerana, S. prostrata and S. fernandeziana. In contrast, S. macrocarpa, an ancient element of the South American flora, is closely related to species belonging to the section Sophora represented in the region by S. tomentosa, S. linearifolia and S. rhynchocarpa. Sections Calia and Styphnolobium are clearly related to each other, both morphologically and chemically. Copyright © 1996 Elsevier Science Ltd.