Elham Aghababaeyan - Faculty of Biological Science, Alzahra University, Sheikh-Bahaee Sq., Tehran, I. R. Iran.
Maneezheh Pakravan - Faculty of Biological Science, Alzahra University, Sheikh-Bahaee Sq., Tehran, I. R. Iran.
Akhtar Tavassoli - Faculty of Biological Science, Alzahra University, Sheikh-Bahaee Sq., Tehran, I. R. Iran.

The somatic chromosome numbers and karyotype of five species of Onopordum L. (Asteraceae) from Iran were investigated. Our results confirm that all of the species are diploid (۲n=۳۴). First chromosome reports are presented for O. leptolepis DC., O. heteracanthum C. A. Mey. and O. carduchorum Bornm & Beauverd. Besides, the chromosome numbers of O. armenum Grossh., O. carduchorum and O. acanthium L. are reported from Iran for the first time, confirm the previous reports. Karyotype formulae for O. armenum, O. carduchorum and O. leptolepis were similar (۱Sm+۱۶m), for O. heteracanthum and O. acanthium were respectively ۱۷m and ۱M+۱۶m+۲B.Satellites were commonly found on submetacentric pairs, being also variable in morphology and location.

Chromosome, Iran, Karyotype, Onopordum