as Saxifragaceae sensu lato (s.l.). Within those subfamilies, the large majority of genera (30) were located within subfamily Saxifragoideae, the core group, with all but two of the remainder only having 1-3 genera. The circumscription of the family has changed considerably in recent years, in large part due to molecular phylogenetic work showing the family s.l. to be polyphyletic, and probably represents the most extreme example, with at least 10 evolutionary lines. Consequently the circumscription has been considerably reduced, with many of the subfamilies being either elevated to separate families, or placed as components of other families, often quite distant. For instance subfamily Parnassioideae was raised to the level of family Parnassiaceae, and eventually a subfamily of Celastraceae (order Celastrales). Similarly the Hydrangoideae is now the family Hydrangeaceae (order Cornales). The reduced Saxifragaceae is distinguished by being referred to as Saxifragaceae sensu stricto (s.s.), corresponding to the Saxifragoideae a natural monophyletic group. Historically, the Saxifragaceae has been placed in either the orders Rosales or Saxifragales. This reduced Saxifragaceae, corresponding to subfamily Saxifragoideae and its 30 genera, is now placed within the Saxifragales. There, with three other subfamilies (Ribesoideaee, Iteoideae and Pterostemonoideae) it forms the Saxifragaceae alliance, while Penthoroideae and Tetracarpaeoideae are closely related within the core Saxifragales as shown in the cladogram. The remaining subfamilies are all transferred to more distant orders within the rosid and asterid clades. Subdivision Numerous attempts have been made to subdivide Saxifragoideae (Saxifragaceae s.s.). These have included dividing the family by the placentation of the ovules, as either parietal (e.g. Heuchera) or axile (e.g. Saxifraga). None of these has been supported by molecular data. Molecular data indicate that the family can be considered as a number of informal clades, with two main lineages, saxifragoids and heucheroids and further subdivision of heucheroids into nine subclades or groups: Clades (Genera (Species)) Saxifragoids (Saxifraga (370)) Heucheroids (remaining genera): Leptarrhena (Leptarrhena (1), Tanakaea (1)) Saniculiphyllum (Saniculiphyllum (1)) Boykinia (Boykinia (6), Bolandra (2), Hieronymusia (1), Jepsonia (3), Sullivantia (3), Suksdorfia (2), Telesonix (2)) Astilbe (Astilbe (23), Saxifragopsis (1)) Heuchera (Heuchera (36), Bensoniella (1), Conimitella (1), Elmera (1), Lithophragma (10), Mitella (20), Tellima (1), Tiarella (3), Tolmiea (1)) Cascadia (Cascadia (1), Saxifragodes (1)) Darmera (Darmera (1), Astilboides (1), Bergenia (10), Mukdenia (1), Oresitrophe (1), Rodgersia (5)) Peltoboykinia (Peltoboykinia (1), Chrysosplenium (55)) Micranthes (Micranthes (70)) The clades and subclades are related as shown in the cladogram: Genera Saxifragaceae s.s. has about 33–35