Chromosome Studies of Native Lowland Diploid Species of Taraxacum (Asteraceae) in Japan

Abstract

Diploid lowland Taraxacum classified as T. elatum, T. hondoense, T. longeappendiculatum, T. japonicum, T, maruyamanum and T. platycarpum according to Kitamura (1957) were studied cytologically. Karyotypic formulae of the 6 forms were as follows: T. platycarpum, 2n=16=2M+10m+4m_cs; T. elatum, 2n=16=12m+4m_cs: T. hondoense, 2n=16=2M+10m+4m_cs; T. longeappendiculatum, 2n=16=12m+4m_cs; T. japonicum, 2n=16=12m+4m_cs; T. maruyamanum, 2n=16=14m+2m_cs. The karyotypes from T. elatum, T. hondoense, T. longeappendiculatum, T. japonicum and T. platycarpum had similar formulae described as 2n=16=12(M+m)+4m_cs. In contrast, that of T. maruyamanum was 2n=16=14m+2m_cs. The karyological data support the taxonomic study by Serizawa (1986, 1995), who treated the native lowland diploid Taraxacum in Japan as 2 species, T. platycarpum and T. maruyamanum.