Abstract: In this paper, the chromosome numbers of two genera Nouelia and Leucomeris (Compositae) are first reported. In Nouelia insignis, 10 populations are studied. The result shows that the chromosome number in different population is consistent, 2n=54, which should be sexiploid.There is only one species of Leucomeris distributed in China. The chromosome numbers of Leucomeris decora is the same as Nouelia insignis 2n=54. Both genera have the same chromosome mumbers, which are also different from the other genera in tribe Mutisiinae. In cytological level, combining some morphological and distribution information, it probably implies that Nouelia is a natural group and there are close relationships between Nouelia and Leucomeris. Nouelia may be descendant of old plants. They developed polyploids for surviving in changing environments.

Key words: Chromosome