Systematic position of Polygonatum simizui (Convallariaceae) based on morphological, cytological and chloroplast DNA sequence data

Polygonatum simizui has been treated as a synonym of P. odoratum s.l., but can be distinguished from R odoratum by having a terete stem, more leaves o n each individual, and relatively small flowers. The results of morphologic al study showed that there exist some regular and correlated variations in plants of R odoratum s.l., and some of them can be identified as R simizui based on the main key characteristics. The results obtained from this study indicate that the morphological differences in plants of R odoratum s.l. a re paralleled by some cytological and molecular characteristics. Four NOR l oci are observed in the chromosomes of plants that can be identified as P. simizui by in situ hybridization with the 18S-5.8S-26S rDNA probes. The bas ic number of chromosome of them is n = 9, which is very different from that of the other plants of R odoratum s.l. The same variation patterns are fou nd in PCR-RFLP analysis of trnK and rpl16 genes. As it seems to be unreason able to include all these plants in a single species, R simizui should be c onsidered to be a distinct species. (C) 2001 The Linnean Society of London.