Nearly half of the species in the large genus Saxifraga belong to Saxifraga sect. Ciliatae, a largely Sino‐Himalayan taxon. We report here that evidence from chloroplast DNA sequences (psbA‐trnH, trnL‐F) and from nuclear sequences (ITS) indicates that this section is monophyletic and composed of at least three main lineages, corresponding to (1) a clade made up of species from S. subsect. Gemmiparae, subsect. Cinerascentes, subsect. Flagellares and subsect. Hemisphaericae, in which the last three subsections are nested in the first; (2) a clade of species belonging to S. subsect. Rosulares (including S. subsect. Serpyllifoliae); and (3) a clade of species belonging to S. subsect. Hirculoideae. Species relationships in S. subsect. Rosulares and subsect. Hirculoideae are not well resolved. A molecular clock analysis indicates that the diversification of S. sect. Ciliatae into its three lineages dates from ca. 9.48 Ma, coinciding with orogenic events associated with one of the most important phases of uplift of the Qinghai‐Tibet Plateau. Extensive diversifications within S. subsect. Rosulares and subsect. Hirculoideae have been more recent (ca. 4.51 Ma and 2.12 Ma, respectively), again correlated with Qinghai‐Tibet Plateau uplift events and, in the case of S. subsect. Hirculoideae, have occurred at a rate comparable to that seen in the radiation of Hawaiian fruit flies.

Details of leaf venation in 150 species of Saxifraga L. representing all 13 sections are reported. Three main patterns were observed: palinactinodromous, acrodromous and camptodromous. Species with lobed leaves have palinactinodromous patterns, whereas those with entire leaves are acrodromous or camptodromous. Thus species from sections Heterisia, Irregulares,  Cymbalaria, Cotylea and Mesogyne are palinactinodromous; species from sections Saxifraga, Ciliatae, Bronchiales  and Trachyphyllum, in which some have lobed and some have entire leaves, are either  palinactinodromous or acrodromous, according to the leaf margin; species from sections Ligulatae and Porphyrion, whose hydathodes secrete calcium bicarbonate, have camptodromous venation. Intermediate states occur in section Gymnopera (between palinactinodromous and camptodromous) and in section Porphyrion subsection Oppositifoliae and section Xanthizoon (intermediate between acrodromous and camptodromous). The pattern of distribution across the genus and selected outgroups shows that the ancestral state is likely to be palinactinodromous.