the first branch in the Crassulaceae+Haloragaceae s.l. tree, i.e. as sister to those two families. The number of genera in each family is shown in parentheses: Families Distribution and habitat Saxifragales are found worldwide, though primarily in temperate zones and rarely in the tropics. They occupy a wide variety of habitats from arid desert (Crassulaceae) to aquatic conditions (Haloragaceae), with 6 families, including North American species, that are obligate aquatic (fully dependent on an aquatic environment), and including forests, grasslands and tundra. Saxifragales exceeds all other comparably sized clades in terms of diversity of habitats. Most of the diversity occurs in temperate (including montane and arid) conditions that expanded globally during cooling and drying trends in the last 15 My. The most common habitats are forests and cliffs, with about 300 species occupying each, but with forests being the most diverse phenotypically, where nearly all families are represented. In contrast desert and tundra, with only two families each, contain only about 10% of species. About 90% of species can be assigned to a single habitat. Conservation Whittonia (Peridiscaceae) is thought to be extinct. the IUCN lists 9 critically endangered, 12 endangered, 19 vulnerable and 7 near threatened species. Among the most threatened Saxifragales are Aichryson dumosum and Monanthes wildpretii (Crassulaceae), Haloragis stokesii and Myriophyllum axilliflorum (Haloragaceae), Ribes malvifolium and R. sardoum (Grossulariaceae), Saxifraga artvinensis (Saxifragaceae) and Molinadendron hondurense (Hamamelidaceae). Uses Plants in the order Saxifragales have found a wide variety of uses, including traditional medicines, ornamental, household, aquarium, pond and garden plants, spices, foodstuffs (fruit and greens), dyestuffs, smoking, resin, timber and roof coverings (see Families). Cultivation A number of Saxifragales genera are commercially cultivated. Paeonia are cultivated both as ornamental shrubs (generally sold as root stock) and for cut flowers, with the Netherlands representing the largest production, other more minor producers are Israel, New Zealand, Chile and the United States. Liquidambar is used for hardwood, with the American Sweetgum (Liquidambar styraciflua) being among the most important sources of commercial hardwood in the Southeast United States, with one of its uses being veneer for plywood. Hamamelis is cultivated in New England for distilleries extracting witch-hazel, widely used in skincare, and is the largest source of this medicament in the world. Among the Crassulaceae, economic importance is limited to horticulture, with many species and cultivars important as ornamentals, including Crassula ovata (jade plant) and Jovibarba (hen and chicken). Hylotelphium, Phedimus, Sedum