Chrysanthemums ( ), sometimes called mums or chrysanths, are flowering plants of the genus Chrysanthemum in the family Asteraceae. They are native to Asia and northeastern Europe. Most species originate from East Asia and the center of diversity is in China. There are countless horticultural varieties and cultivars.
Chrysanths, chrysanthemums, and mums are different names for the same type of flower. 
The context states that chrysanths and mums are alternative names for chrysanthemums, so they are all the same thing. The system was likely confused by there being multiple names to refer to one type of flower. 