Rhodiola

Rhodiola
Rhodiola heterodonta
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Core eudicots
Order:	Saxifragales
Family:	Crassulaceae
Genus:	Rhodiola L.
Species
Dozens. Included under Sedum at Wikispecies.

This article is about the plant genus. For the particular species widely used in herbal medicine (as "golden root", "roseroot", etc.), see Rhodiola rosea.

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.

The Holarctic species Rhodiola rosea is used in herbal medicine. A number of species are grown as ornamentals, but growing them is difficult outside their native subarctic and alpine climates.

The name combines the Greek rhodon, meaning rose and referring to the rose-like smell of the roots, with the Latin diminutive suffix -iola.

Chemical composition

Rhodionin is a herbacetin rhamnoside found in Rhodiola species.

Species list

Species include:

• Rhodiola integrifolia
• Rhodiola rhodantha
• Rhodiola rosea