Bergenia is a genus of ten species of flowering plants in the family Saxifragaceae (order Saxifragales), native to central Asia — from Afghanistan east through the Himalayan region to China — and extending north into Kazakhstan, Siberia, and the Russian Far East. The genus was described by Conrad Moench in 1794 and named in honour of the German botanist and physician Karl August von Bergen.
Plants are clump-forming, rhizomatous, evergreen perennials. The leaves are large, leathery, ovate to cordate, 6–35 cm long, arranged in a basal rosette; they remain glossy green through most of the year but take on red or bronze tones in autumn in cooler climates. Flowers are borne on stout, rhubarb-red stems in cymes and range from near-white through pink to carmine-red and purple. Plants typically reach 30–60 cm in height and spread.
The genus is closely related to Mukdenia, Oresitrophe, Astilboides, and Rodgersia within the Saxifragaceae. Common names reflect distinctive leaf characters: elephant's ears (size and shape) and pigsqueak (the squeaking sound produced when two leaves are rubbed together).
Bergenia crassifolia (Siberian tea, thick-leaved bergenia) is the most widely cultivated species, with numerous garden cultivars selected for leaf colour and flower shade. Bergenia purpurascens from the central Himalayas and south-central China is notable for its deep carmine-red flowers.
Rhizomes of several species — notably B. ciliata, B. ligulata (syn. B. pacumbis), and B. stracheyi — yield bergenin and norbergenin, C-glycoside compounds used in Ayurvedic medicine (Paashaanbhed) and studied for immunomodulatory properties.
Etymology
The genus name Bergenia was coined by the German botanist Conrad Moench in 1794 to honour Karl August von Bergen (1704–1759), a German botanist and physician. The common name "pigsqueak" refers to the squeaking sound produced when two leaves are rubbed together; "elephant's ears" describes the large, rounded leaf shape.
Distribution
Bergenia is native to central Asia, ranging from Afghanistan and Tajikistan east through the Himalayan region (Nepal, Bhutan, northern India) to Myanmar and China (Yunnan, Sichuan, Shaanxi), and north into Kazakhstan, western Siberia, and the Russian Far East. Individual species occupy distinct sub-ranges within this arc: B. hissarica is restricted to western Uzbekistan, B. ugamica to eastern Uzbekistan, B. crassifolia extends into Kazakhstan and Korea, and B. emeiensis is endemic to Sichuan.
Cultivation
Bergenia are exceptionally hardy garden plants, tolerating temperatures from approximately −37 °C to 46 °C. They grow in full sun to full shade and reach about 60 cm in height and spread. Most soils are suitable, though moist, humus-rich conditions are preferred; dry or exposed sites stunt growth but can intensify autumn leaf colour. Propagation is by division of clumps or by rooting rhizome sections. Bergenia crassifolia, B. cordifolia, and various named hybrids are widely grown, and several cultivars hold the Royal Horticultural Society's Award of Garden Merit.
Cultural Uses
Rhizomes of B. ciliata, B. ligulata (= B. pacumbis), and B. stracheyi contain bergenin and its derivative norbergenin — C-glycosides of 4-O-methyl gallic acid used in Ayurvedic medicine under the name Paashaanbhed. These compounds have been investigated for immunomodulatory activity. Leaves of B. crassifolia have historically been used as a tea substitute in parts of Siberia and Central Asia.
