17. Doellingeria Nees
Three species, U.S., Canada.
Doellingeria was long treated by most North American
botanists as a relatively distinctive small subgenus within a broadly
circumscribed Aster. Molecular analyses have suggested that the group
comprises the most primitive lineage of North American asters (Noyes and
Rieseberg, 1999; Semple et al., 2002). There has been some controversy over
whether eight closely related Asian species should be included in the genus
(Nesom, 1993b, 1994, 2000), but the most recent studies indicate that the Asian
species are more closely related to other Old World asters.