Editing Saxifragaceae (section)

=== Subdivision ===
[[File:American Alumroot Heuchera americana 'Garnet' Stalk 2448px.JPG|thumb|upright|''[[Heuchera americana]]''|alt=Flower stalk of Heuchera americana]]
[[File:Rodgersia podophylla 4587.jpg|thumb|upright|''[[Rodgersia podophylla]]''|alt=Flowers of Rodgersia podophylla]]
[[File:Saxifraga merkii var idsuroei s2.jpg|thumb|upright|''[[Micranthes merkii]]''|alt=Flowers of Micranthes merkii]]

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.{{sfn|Byng|2014}}{{sfn|Soltis et al|1993}}

[[molecular phylogenetic|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:{{sfn|Soltis et al|1993}}{{sfn|Deng et al|2015}}{{sfn|Byng|2014}}
;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 (''[[Saxifraga|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:{{sfn|Deng et al|2015}}
{{cladogram|title=Cladogram II: Infrafamilial structure of Saxifragaceae
|caption=Diversification time in Mya underneath group names
|align=left
|cladogram=
{{clade|style=font-size:90%;line-height:100%
|label1='''Saxifragaceae'''
|sublabel1=38
|1={{clade
    |label1=Saxifragoids
    |sublabel1=30
    |1=''Saxifraga''
    |label2=Heucheroids
    |sublabel2=31
    |2={{clade 
      |1={{clade
     |sublabel1=20
        |1={{clade
          |sublabel1=18
          |1={{clade
             |sublabel1=8
             |1=Leptarrhena
             |sublabel2=16
             |2={{clade
               |1=''Saniculiphyllum''
               |sublabel2=11
               |2=Boykinia
                }}
             }}
             |sublabel2=14
             |2=Astilbe
             }}
         |2={{clade
          |1={{clade
           |sublabel1=7
           |1=Heuchera
           |sublabel2=29
           |2={{clade
           |1={{clade
                |sublabel1=19
                |1=Cascadia
                |sublabel2=10
                |2=Darmera
                }}
             |sublabel2=27
             |2={{clade
                |sublabel1=23
                |1=Peltoboykinia
                |sublabel2=15
                |2=''Micranthes''
                }}
           }}
}}
}}
}}
}} 
}}
}}
}}
{{Clear}}

==== Genera ====
{{main|List of Saxifragaceae genera}}
Saxifragaceae ''s.s.'' has about 33–35 genera and about 640 species. About half of the genera (18 of 33) are [[monotypic]], but ''Saxifraga'' has about 400 species, and has generally been divided into sections.{{sfn|Soltis et al|1993}}{{sfn|Christenhusz|Byng|2016}}{{sfn|Christenhusz et al|2017}}{{sfn|Deng et al|2015}}