THE KARYOTYPE ANALYSIS OF XANTHIUM MONGOLICUM
蒙古苍耳核型分析

The number and karyotype of chromosomes of Xanthium mongolicum Kitag.were studied.The results showed that the chromosome number of the species is 2n=36and its karyotype formula is K(2n)=36=26m 2m(SAT) 8sm, as same as those of Xanthium sibiricum Patrin. X. mongolicum belongs to type "1A" of Stebbins' karyotype asymmetry. Upon a comparison of the karyotype of X. mongolicum with that of X.sibiricum Patrin,it has been found that the latter belongs to type"2B", and should,therefore, be considered as more advanced than the former.