Chloroplast DNA restriction fragment length polymorphisms have been used to reconstruct the maternal phylogeny of all the known taxa in the small neotropical legume genus Leucaena. Three major plastome clades were recognized, but these did not conform with relationships between the taxa proposed on other characters from morphology, cytology or hybridization. The maternal parentage of tetraploids within the genus has been proposed. Evidence for introgression was found between diploid L. diversifolia and tetraploid L. diversifolia. The implications of these results for the origin of the cultivated taxa are discussed.
Harris, S.A.; Hughes, C.E.; Ingram, R.; Abbott, R.J. A phylogenetic analysis of Leucaena (Leguminosae: Mimosoideae). Plant Systematics and Evolution (1994) 191 (1/2) 1-26.