Polyploidy and apomixis in accessions of Senna rugosa (G.Don) H.S.Irwin & Barneby

Senna rugosa (G.Don) H.S.Irwin & Barneby (Leguminosae) is a species from the Brazilian Cerrado commonly used for medicinal purposes. Chromosome variability (n = 14 and 28) described for this species indicates the occurrence of chromosome races and recent polyploidization in its evolution history.