Abstract: Chromosome numbers of 13 taxa and 12 crossing combinations in the Magnoliaceae are reported. The counts of 12 taxa are reported for the first time. The intergeneric crossing combination between Magnolia×soulangeana “Hongyuanbao” (♀), a tetraploid with 2n=4x=76, and Michelia yunnanensis (♂), a diploid with 2n=2x=38, had the number of 2n=3x=57, a half of the total chromosome number of its parents. Similarly, the intergeneric crossing combination between Magnolia×soulangeana “Hongyuanbao” (♀) and Michelia foveolata (♂), a diploid with 2n=2x=38, also had the number of 2n=3x=57. These indicate that the offspring of the two crossing combinations are true hybrids.

Key words: Key words Magnoliaceae, chromosome number, hybrid identification.