Rhodiola rosea extract
Rhodiola is a genus of perennial plants in the family Crassulaceae that resemble Sedum and other members of the family. Like sedums, Rhodiola species are often called stonecrops. Some authors merge Rhodiola into Sedum. Rhodiola species grow in high-altitude and other cold regions of the Northern Hemisphere. Den virtuella floran gives the number of species as 36, the Angiosperm Phylogeny Group gives it as 60, and the Flora of China gives it as about 90, with 55 in China and 16 endemic there. The USDA Plants database lists only 3 species in the United States and Canada. Among the distinguishing characters of the genus are two series of stamens totaling twice the number of petals; free or nearly free petals (not joined in a tube); a stout rhizome from whose axils the flowering stems rise; and a basal rosette of leaves. This genus contains the only species of Crassulaceae that have unisexual flowers.