Key points are not available for this paper at this time.
David R. Morgan, Douglas E. Soltis, Phylogenetic Relationships Among Members of Saxifragaceae Sensu Lato Based on rbcL Sequence Data, Annals of the Missouri Botanical Garden, Vol. 80, No. 3 (1993), pp. 631-660
Morgan et al. (Fri,) studied this question.