''Rhodiola integrifolia'' is a species of flowering plant in the stonecrop family known by the common names ledge stonecrop, western roseroot, and king's crown. It is native to north-easternmost Russia, including Kamchatka, and western North America, where it grows in mountainous habitat in

subalpine Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...

and

alpine climate Alpine climate is the typical weather ( climate) for elevations above the tree line, where trees fail to grow due to cold. This climate is also referred to as a mountain climate or highland climate. Definition There are multiple definitions ...

s, including meadows, cliffs, and talus. It is a perennial herb producing a stout stem from a fleshy, branching

caudex A caudex (plural: caudices) of a plant is a Plant stem, stem, but the term is also used to mean a rootstock and particularly a basal stem structure from which new growth arises.pages 456 and 695 In the strict sense of the term, meaning a stem, " ...

, reaching a maximum height near 30 centimeters. The fleshy leaves are alternately arranged on the stem, widely lance-shaped to oval and pointed, flat but upcurved toward the tip, reaching 2.5 centimeters long. They are green when new and age to orange, rose, or red. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed ...

is a dense cyme of up to 50 flowers with fleshy petals in shades of bright red to deep purple. The fruits are red, rounded ovals with pointed tips. There are several subspecies of this plant, with one, ssp. ''leedyi'', very rare and limited to a few populations in

Minnesota Minnesota () is a state in the upper midwestern region of the United States. It is the 12th largest U.S. state in area and the List of U.S. states and territories by population, 22nd most populous, with over 5.75 million residents. Minne ...

and

upstate New York Upstate New York is a geographic region consisting of the area of New York State that lies north and northwest of the New York City metropolitan area. Although the precise boundary is debated, Upstate New York excludes New York City and Long ...

.Center for Plant Conservation
This subspecies is considered a

relict A relict is a surviving remnant of a natural phenomenon. Biology A relict (or relic) is an organism that at an earlier time was abundant in a large area but now occurs at only one or a few small areas. Geology and geomorphology In geology, a r ...

from times when its range was covered in

glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such a ...

s; it survives on barren cliffs which are kept cold by air blowing through cracks from

cave A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word ''cave'' can refer to smaller openings such as sea ...

s. It is treated as a federally listed threatened species in the United States.

References

External links

Jepson Manual Treatment

Washington Burke Museum

Photo gallery

Flora of the U.S.S.R. (as R. atropurpurea)
Crassulaceae Taxa named by Constantine Samuel Rafinesque {{Crassulaceae-stub