Shrub or woody vine
Woody vine; petals 7 or more........................Decumaria
Shrub; petals 4 or 5
Leaves alternate or on short spur branches
Leaves pinnately veined; ovary superior...................Itea
Leaves palmately veined; ovary inferior..................Ribes
Leaves opposite
Petals usually 4; stamens 20-40....................Philadelphus
Petals usually 5; stamens 8-10.......................Hydrangia
Herbs
Staminodia present; petals more than 10 mm long............Parnassia
Staminodia absent; petals less than 10 mm long
Leaves ternately decompound......................................Astilbe
Leaves simple
Flowers solitary in leaf axils, or in short, leafy cymes
Sepals 4; carpels 2.........................Chrysosplenium
Sepals 5; carpels 3..........................Lepuropetalon
Flowers in racemes or panicles
Petals pinnatifid or fringed; stem leaves opposite..........Mitella
Petals not pinnatified or fringed; stem leaves alternate or absent
Ovary 1- celled
Inflorescence paniculate; stamens 5...........Heuchera
Inflorescence racemose; stamens 10...............Tiarella
Ovary 2-celled
Stamens 5; leaves palmately lobed...............Boykinia
Stamens 10; leaves not palmately lobed.......Saxifraga
(Radford, Ahles & Bell)