Bergenia Moench
Bergenia is a small Asian genus with about 6-10 species (Pan & Soltis 2001). Nearly all are grown as ornamentals, as are several hybrids (e.g. Yeo 1995, Jäger & al. 2008, Stace 2010). At present plants in gardens are probably mostly hybrids and their identity is often difficult to assess. The same applies to plants currently found in the wild. These are often mere relics of former cultivation or more or less established garden throw-outs (and do not depend on sexual reproduction). It is uncertain which are found in Belgium at present, although there are at least 2 or 3 more or less distinct taxa. Further research is required and the current account therefore is a provisional one. Plants with ciliate leaf margins, horizontal to erect purplish flowers and a sparsely ciliate inflorescence axis are here referred to B. xschmidtii. Those with glabrous leaf margins at least seem to pertain to two different species, one with deeply cordate leaf bases (here referred to as B. cordifolia) and one with wedge-shaped leaf bases (here referred to as B. crassifolia). Some plants with more or less intermediate features may belong to their hybrid, B. xmedia (Haw.) Engl. (Stace 2010) but this also requires confirmation.
The degree of naturalization and distribution of these taxa in Belgium is – for evident reasons – unclear.
1 Leaf margin quite glabrous or occasionally with a few ciliae at base only === 2
Leaf margin ciliate throughout === Bergenia xschmidtii
2 Leaves circular with clearly cordate base. Petals usually with a distinct claw === B. cordifolia
Leaves ovate, blade wedge-shaped at base. Petals tapered at base === B. crassifolia
Literature
Beckett K.A. (1983) Bergenia. Garden (London) 108(12): 480-484.
Jäger E.J., Ebel F., Hanelt P. & Müller G. (eds.) (2008) Rothmaler Band 5. Exkursionsflora von Deutschland. Krautige Zier- und Nutzpflanzen. Springer Verlag, Berlin: 880 p.
Kumar A. (1997) Taxonomic account of four families of angiosperms in Madhya Pradesh, India. J. Econ. Taxon. Bot. 21(1): 123-128.
Menell M. (1982) Portrait of the genus Bergenia North. Gard. 36(2): 52-54.
Pan J.T. (1988) A conspectus of the genus Bergenia Moench. (in Chinese). Acta Phytotax. Sin. 26(2): 120-129.
Pan J. & Soltis D.E. (2001) Bergenia. In: Wu Z.Y. & Raven P.H. (Eds.) Flora of China 8. Science Press, Beijing & Missouri Botanical Garden Press, St. Louis: 278-280. [available online at: http://flora.huh.harvard.edu/china/PDF/PDF08/BERGENIA.pdf]
Stace C. (2010) New flora of the British Isles, 3th ed.: XXXII + 1232 p. Cambridge University Press.
Yeo P.F. (1961) Two Bergenia hybrids. Baileya 9: 20-28.
Yeo P.F. (1966) A revision of the genus Bergenia. Kew Bull. 20: 113-148.
Yeo P.F. (1971) Further observations on Bergenia in cultivation. Kew Bull. 26(1): 47-56.
Yeo P.F. (1972) Cultivars of Bergenia in the British Isles. Baileya 18: 96-112.
Yeo P.F. (1995) Bergenia. In: Cullen J. & al. (eds.), The European Garden Flora, vol. 4. Cambridge University Press, Cambridge: 250-251.