A phylogeny inferred from large ribosomal subunit (26S) rDNA sequences suggests that Cuscuta is a derived member of Convolvulaceae

Cuscuta is a parasitic angiosperm that has been considered alternatively either as a genus within Convolvulaceae or as a monogeneric family in its own right. Although typically placed in the Solanales, Cuscuta has also been positioned within the Polemoniales. Extreme reduction of morphological and anatomical characters, as well as chloroplast genome reductions and rearrangements, has made the phylogenetic placement of Cuscuta uncertain. Analysis of 26S rDNA sequences suggests that Cuscuta is a derived member of Convolvulaceae. Molecular results are discussed in relation to the morphological and anatomical characters of autotrophic members of Convolvulaceae.