572. BERGENIA EMEIENSIS Saxifragaceae Mikinori Ogisu and Martyn Rix Summary. Bergenia emeiensis C.Y. Wu ex J.T. Pan is illustrated and described. Its relationship to other Himalayan species is discussed, and instructions for its cultivation are given. The genus Bergenia Moench consists of around 10 species of stemless, rhizomatous, herbaceous plants, with large rounded, stalked leaves and a many-flowered leafless inflorescence. All the species originate in Asia, growing in the mountains from Lake Baikal to the Pacific coast of Siberia, westwards through China to the western Himalaya in Afghanistan. Bergenia emeiensis is the sixth species of the genus to be illustrated in Curtis’s Botanical Magazine. When listing Père Armand David’s collections from Moupine (today Baoxing), Franchet (1886) described var. macrantha of Saxifraga purpurascens Hook. fil. & Thoms. This had petals around 25 mm long, obovate-oblong, and a lax few-flowered inflorescence with sessile glands. Franchet concludes his account with “cette belle saxifrage devra peut-être constituer une espéce nouvelle sous le nom de S. macrantha.”. There is no indication in Franchet’s description that the flowers of var. macrantha Franchet were white. Peter Yeo (1966), published a detailed account of the genus Bergenia, including all the interspecific hybrids which had been produced in cultivation. At that time, of the six species he recognised, only B. purpurascens (Hook. fil. & Thoms.) Engler was recorded from central China. He discussed Franchet’s var. macrantha, but concluded that the characters on which Franchet based the variety vary independently in B. purpurascens, and therefore that it would not be possible to use them to distinguish a variety. Two specimens at Kew from western Sichuan, Wilson 3584 and Limpricht 1319 from Wen Chuan Hsien at 1800–2000 m, have the lax inflorescence and long petals (1.8–2.2 cm) of Franchet’s var. macrantha, but they have toothed or ciliate leaf margins. There is no indication that either of these collections had white flowers. C.Y. Wu (1988) described Bergenia emeiensis from Emeishan or Mount Omei, and distinguished it from B. purpurascens by its narrower entire, obovate leaves, by the ciliate margins of the ochrae, 2 © The Board of Trustees of the Royal Botanic Gardens, Kew 2007. Published by Blackwell Publishing Ltd, 9600 Garsington Road, Oxford, OX4 2DQ UK and 350 Main Street, Malden, MA 02148, USA Plate 572 Bergenia emeiensis ANDREW BROWN by the sparsely glandular inflorescence and by the white flowers. In B. purpurascens the glandular hairs on the inflorescence are usually dense and long-stalked. In plants cultivated in England, the leaves of B. emeiensis are very thick and leathery, evergreen and remain dark green through the winter, whereas most leaves of B. purpurascens become red or purple in winter, and are of distinctly thinner texture. The marginal leaf teeth of B. emeiensis are shorter and much less conspicuous than those of B. purpurascens. Although it was not described as a new species until 1988, the type plant had been collected by T.H. Tu (Tu 240) in 1935, on cliffs at around 1600 m. More recent collections have been from Baoxing where it was found by T.P. Soong, and more recently by Mikinori Ogisu. Other records are from the Wenjinjian valley in Chongqing county and at Dujiangyan, both in Sichuan. Roy Lancaster (1996) describes the habitat of Bergenia emeiensis in some detail; in most sites it grows in alkaline soils over rocks of various kinds, normally in a fairly dry situation and usually under an overhang. Most colonies were in open rather than shady sites, but with no direct rainfall. The only available moisture reaches these plants as seepage from higher ground. In Baoxing Bergenia emeiensis was seen growing on cliffs and at the top of a rock face, and is under some threat as the whole area is being removed to utilise a deposit of a very pure, white marble, comparable with that from Carrara. Lorries carry huge blocks from the rock face to the town of Baoxing, where it is either sliced into sheets or carved into statues of Giant Pandas, Michelangelo’s David, or the Venus of Milos. A large statue of Père David himself stands outside the Baoxing hotel. A pink-flowered variety of Bergenia emeiensis, var. rubellina Pan (1994), was recorded from a much higher altitude, 3500–3900 m, but we have not seen the type specimen. Pan described a second species from western Sichuan in the same paper. This was Bergenia tianquanensis Pan, found in rock crevices at 2200–3300 m near Tianquan. It has reddish flowers with petals 1.6 cm long and ciliate leaves. Another Chinese species, Bergenia scopulosa T.P. Wang, was described from the Tsinling mountains in Shensi. It has smooth ochrae and a completely glabrous inflorescence; in its large leaves with orbicular blades and the purplish-pink flowers it is very distinct (Wang 1974). © The Board of Trustees of the Royal Botanic Gardens, Kew 2007. 3 Bergenia emeiensis is similar in many ways to white-flowered forms of B. strachyi, particularly in its small, obovate leaf blades, but the leaves of B. strachyi are ciliate and the base rounded or acute, not cuneate. B. strachyi is a high alpine plant, reaching 4500m in western Tibet, and otherwise found only in the western Himalaya. The plants from which our illustration was drawn were collected by Mikinori Ogisu in 1982 at an altitude of 1750m on Mount Omei (Ogisu 82003). Plants from this collection came to Kew in 1996 via Blackthorn Nursery in Hampshire. CULTIVATION. This species thrives in an unheated greenhouse or frame, planted in a pot. Because of its early flowering, often in February, the added protection saves the flowers from damage by Bergenia emeiensis. A, lateral view of flower; B, part of perianth (3 sepals and 3 petals, opened to show insertion of filaments); C, petal; D, two sepals, inner face, * indicates vein to petals; E, section of flower, all petals and 3 stamens removed to show ovaries, styles and stigmas; F, ovaries showing loculi sectioned vertically; G, stigma; H, t/s of ovary at x—x in F; I, erect flower 40 days older than A, showing sepals held horizontally, persistent petals and stamens, ovaries somewhat shrivelled, seeds abortive; J, seed, 3 views. Scale: single bar =1 mm, double bar = 10 mm. Drawn from Ogisu 82003 by Andrew Brown. 4 © The Board of Trustees of the Royal Botanic Gardens, Kew 2007. Bergenia emeiensis in China, Sichuan, near Chongqing, on limestone cliffs at 1370 m, flowering in April 1996. Photo Mikinori Ogisu. late frosts. It has thrived in a soil of half leafmould and half shellrich sand which provides a small amount of lime. In summer the pots are placed at the base of a north wall before being brought under cover in December. Under these conditions the leaf blades grow larger than normal, reaching 20 cm long. Flowering has been improved by a high potash feed in late summer. No diseases have been encountered and the main danger has been the grubs of vine weevils (Otiorhynchus species), which can remove the outer layer from the fleshy rhizomes, and severely weaken the plants. Plants at Kew are grown in a wide, deep pan that is plunged in sand in a cold frame against a north-facing wall. This provides some shade, as well as protection from frost and excess rain in winter but, with the frame lights open, allows excellent ventilation at other times. In early spring this species is displayed in the Davies Alpine House. When exhibited by Kew at a London RHS show on 19 February 2002, Bergenia emeiensis received a First Class Certificate. As it comes from a comparatively low altitude in a warm, wet climate, Bergenia emeiensis has been mentioned as being potentially useful for bringing more heat-tolerance into the genus. The genus, however, is already remarkable for the range of habitats the species can tolerate. Both B. crassifolia, the commonest species in cultivation in the past and B. cordifolia, are happy in gardens in Mediterranean climates, and the former is used, rather inappropriately, in the gardens of the Alhambra in Granada; both, of course can survive Siberian winters. Bergenia emeiensis C.Y. Wu ex J.T. Pan, Act. Phytotax. Sin. 26 (2):124 (1988). Type: Sichuan, Emei Shan, in fissures rupium, alt. 1590m, 11.vi.1935, T.H. Tu 240, holotype: PE; Baoxing, T.P. Soong 38179. DESCRIPTION. Herbaceous perennial, c. 37 cm tall, with a thick rhizome, elongated and covered with dark scales. Leaves all basal, with a coriaceous lamina, narrowly obovate, cuneate at the base, completely glabrous, blade around 18 cm long. Petiole 3–4.7 cm, glabrous. Sheath flaps with marginal cilia. Scape smooth, simple. Cyme paniculate, c. 18 cm long (to 35 cm in cultivation). Pedicels 2–3 cm long, with sparse subsessile glandular hairs, suffused with red. Flowers rather few, nodding, on an inflorescence which becomes lax during flowering, finally becoming upright as they fade. Sepals coriaceous, narrowly ovate, c. 6 mm long, 5 mm wide, apex obtuse, glabrous on the margin and beneath, with subsessile glandular hairs on the back. Petals at anthesis pure white, becoming pinkish at the base, narrowly obovate, 2.5–2.8 cm long, 9.5–2.1 cm wide, apex obtuse, base extended into a c. 3 mm long, narrow claw. Stamens c. 1.65 cm long. Ovary ovoid, c. 9.5 mm long, style c. 1.1 cm long. © The Board of Trustees of the Royal Botanic Gardens, Kew 2007. 5 DISTRIBUTION. China, Sichuan: Emei shan, Baoxing, Chongqing, Dujiangyan. HABITAT. Cliffs and overhanging rocks, usually on limestone, 1200–1600 m. FLOWERING TIME. March to June. ACKNOWLEDGEMENTS. The authors would like to thank Richard Wilford for his comments and for the details of cultivation at Kew. REFERENCES Franchet, A.R. (1886). Plantae Davidianae ex Sinarum Imperio II. Paris. Lancaster, Roy, (1996). Bergenia emeiensis. The Garden: vol. 121 pt 2: 80–81. Pan, J.T., (1994). New Taxa of the genus Bergenia from Hengduan mountains. Acta Phytotaxonomica Sinica 32: 571. Yeo, P.F. (1961). Two Bergenia hybrids. Baileya ix: 20. Yeo, P.F. (1966). A revision of the genus Bergenia Moench. Kew Bulletin 20 (1): 113–148. Wang, T.P. (1974). Bergenia scopulosa. Flora Tsinling 1(2): 433. 6 © The Board of Trustees of the Royal Botanic Gardens, Kew 2007.