Seventy-three plastid DNA sequences from the trnL-F region were used to inf
er phylogenetic relationships among Polygalaceae. The analysis indicates th
at Xanthophyllum is the sister group to the remainder of genera in Polygala
ceae. Monophyly of tribes Polygaleae and Carpolobieae is corroborated, wher
eas monophyly of Moutabeae could not be confirmed. Although intergeneric re
lationships within Polygaleae are poorly resolved, most traditional genera
are corroborated as monophyletic. However, Polygala and Bredemeyera s.l. fo
rm two exceptions and are grossly polyphyletic. Acanthocladus and Badiera (
incl. Hebecarpa), taxa often assigned to Polygala, are more closely related
to Bredemeyera s.str. than to other Polygala. Likewise, Bredemeyera s.l. i
s broadly polyphyletic since Comesperma and Bredemeyera colletioides (sect.
Hualania) have their closest relatives among other genera. Furthermore, Hu
alania is also polyphyletic since Bredemeyera microphylla appears as the si
ster to the Hebecarpa-Badiera clade. Unlike a previous morphological analys
is, Monnina is strongly supported as monophyletic by trnL-F data, but inter
nal relationships are partly unresolved. Species of Polygala sensu Chodat h
ave a tendency to group by geographical distribution rather than after trad
itional sectional affiliation. Thus, although resolution is poor, it is sus
pected that several sections of Polygala are not monophyletic and need to b
e recircumscribed.