A TAXONOMIC INVESTIGATION OF CUSCUTA ATTENUATA (CUSCUTACEAE) AND RELATED TAXA

摘要

Examination of the taxonomic relationships of the rare parasitic vine Cuscuta attenuata Waterf. to other species of the genus reveals that it should be positioned in subsect. Indecorae Yunck. rather than Lepidanche Engelm. as previously placed. Analyses of morphological variation, via univariate analysis, UPGMA clustering, principal component analysis, and discriminant analysis, indicate that it is distinct from C. compacta Juss. and C. cuspidata Engelm. but morphologically similar to C. indecora Choisy, especially var. longisepala Yunck. Results obtained in a program of interspecific hybridizations reveal that C. attenuata is reproductively isolated from the other taxa. These data suggest that C. attenuata merits continued recognition as a distinctspecies.