A cytotaxonomic study of some Australian species of Drosera L. (Droseraceae)

Abstract

KONDO, K. & LAVARACK, P. S., 1984. A cytotaxonomic study of some Australian species of Drosera L. (Droseraceae). Karyomorphological comparisons of 15 species of Australian Drosera are presented along with 11 new chromosome counts. In Australia the genus forms an extensive aneuploid series. The species which have chromosome numbers from n=10 to n= 19 show large chromosomes, while those which have chromosome numbers more than 20 show small chromosomes. Drosera paleacca shows the lowest chromosome number in the genus, 2n= 10, with 10 large chromosomes, indicating a new basic number, x = 5. The non-staining gap between the chromatids of each chromosome is rather wide and their centromeric region is not seen throughout prophase, prometaphase, and metaphase. The C-banding and silver-staining analyses in Drosera petiolaris chromosomes suggest that Drosera chromosomes could have diffuse centromeres and simplified C-segments. Some taxonomic implications are considered, notably the possible removal of Drosera banksii from Drosera section Ergaleium to Drosera section Lasiocephala and the reduction to synonymy of Drosera section Prolifera.