There was a revision of the genus; Annals of the Missouri Botanical Garden, pp. 79–191 Vol 94, Issue 1 (April 2007)
 Link to abstract here; 
http://tinyurl.com/6oz4sn If you search on Google for "Flora of China draft Ainsliaea"  you should get an HTML file with a key, including Korea and Japan if the species is present there also.
 Many of the species are all highly attractive garden plants, like Prenanthes, Cacalia, Polymnia, etc.
 Aaron Floden
 Knoxville, TN