KARYOSYSTEMATICS STUDY OF SOME ASTERACEAE SPECIES (COMPOSITAE) IN SAUDI ARABIA

Chromosome numbers were reported for 10 species of family Asteraceae from Saudi Arabia. The new count was reported in Pulicaria schimperi L. Karyotype analysis were made for all species, Conyza bonariensis (L.) Cronquist 2n=18, Bidens pilosa L., 2n=70, Pluchea dioscoridis (L.) DC. 2n=32, Pulicaria schimperi L. 2n=12, Lactuca serriola L. 2n=18, Launaea capitata (Spreng.) Dandy 2n=18, Launaea resedifolia (L.) Kuntze 2n=18, Launaea nudicaulis (L.) Hook. F. 2n=18, Reichardia tingitana (L.) Roth 2n=16, and Sonchus oleraceus L. 2n=32, belonging to 4 tribes: Astereae, Heliantheae, Inulea and Lactuceae. Pulicaria schimperi L. has the lowest chromosome number (2n=12), while the highest number of (2n=70) is recorded in Bidens pilosa L.