KARYOMORPHOLOGY AND RELATIONSHIPS OF THE GENUS CIRCAEASTER MAXIM.
星叶草属的核形态及其系统位置

Investigated in this paper was the karyomorphology of the monotypic genus Cir-caeaster Maxim. The interphase nuclei and the prophase chromosomes were categorized to be simple chromocenter type and interstitial type respectively; the metaphase chromosomes were rather small, ranging from 3.00 f33m to 1.20 f33m in length. The karyotype was formulated as 2n= 30 = 22m 8sm. Its distinctive higher haploid chromosome number, together with its several highly reduced and specialized character states in morphology, suggests that Cir-caeaster is a relictual paleopolyploid group. The similar karyomorphological characteristics of interphase nuclei and prophase chromosomes between Circaeaster and Kingdonia, as well as the similar size and morphology of their metaphase chromosomes, support the viewpoint that they are closely related and are probably best treated as a ditypic family.