The Saxifragales is a morphologically-diverse order of 13 families and around 2300 species of dicotyledenous flowering herbs (insect-pollinated), shrubs and trees (wind-pollinated).
Order Saxifragales includes saxifrages, peonies (Paeoniaceae), gooseberries, blackcurrants and redcurrants (Grossulariaceae), sweet gums (Altingiaceae) and witch hazels (Hamamelidaceae). The Saxifragales includes families formerly distributed in other orders including Rosales, Haloragales, and Hamamelidales but molecular analysis supported regrouping.
Crassula helmsii (Australian swamp stonecrop) is a noteworthy invasive hardy species that grows from a small segment of stem, spreads rapidly and chokes waterways with floating mats of weed. Amazingly, it is still distributed through the water-gardening and aquarist trade.
Succulent genera: Most of the succulent species are in the large family Crassulaceae, which contains around 1500 species, although some alpine Saxifragaceae might be considered borderline succulent.