Cephlanthera damasonium -plant of the month June 2013
Cephlanthera is a genus within the massive Orchidaceae family and comprises around 15 currently recognised species which are native to Europe and Asia, with one species C. austiniae being found in North America. Along with the genus Epipactis, these are commonly known as 'Helleborines' but this name does not conform to any modern taxon.
Cephlanthera damsonium favours calcareous soils - mostly beechwoods - where it can be found in quite dense shade. Pollinating insects are uncommon in such areas so self-pollination (autogamy) is the main method of fertilisation for such individuals. Before the flowers open, the anthers deposit the pollinia directly onto the stigmatic surface. A clue to this self-fertilisation process can be seen by the fact that the flowers remain almost closed throughout their flowering period, with no great need to attract insects.
Cultivation is very difficult with any of this genus because of their myco-heterotrophic relationship with fungi - in this relationship, the plant parasitises it host, either fully or partially to obtain food although Cribb and Bailes (Hardy Orchids - Orchids for the garden and frost-free greenhouse; TimberPress) suggest they should grow well in containers comprising mainly loam, grit and beech/oak leafmould with added lime.
The images shown here were taken in The Mendel University Botanical Gardens and Arboretum in Brno, Czech Republic where I was told it can be a problematic weed!