Dactylorhiza purpurella (northern marsh orchid)
Dactylorhiza purpurella (northern marsh orchid) (Photo: Matti Niissalo)
Dactylorhiza purpurella (T.Stephenson & T.A.Stephenson) Soó
northern marsh orchid
Not evaluated according to IUCN Red List criteria; listed in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).
Damp or wet habitats with calcareous, neutral or slightly acid soils, such as marshy fields, road verges, lake margins, fens, marshes, flushes, coastal cliffs, dune slacks, and sometimes peat bogs and open woodland.
About this species
Dactylorhiza purpurella is difficult to distinguish from other marsh orchids, such as D. praetermissa, and was not described as a separate species until 1920. Northern marsh orchid can be recognised by its lip marked with dark spots and lines that do not usually form loops, as well as by its vivid purple-violet flower colour.
Dactylorhiza is one of the most complex orchid genera. It comprises about 50 often poorly defined species. Most occur in Eurasia, but two species are also found in North America.
The name Dactylorhiza derives from the Greek words daktylos meaning finger and rhiza meaning roots, referring to the finger-shaped underground tuber typical of members of this genus.
Geography and distribution
Northern marsh orchid occurs throughout the northwestern part of Europe. It is found in southwestern Norway, southern Sweden, Denmark (including the Faroe Islands) and the UK. In the UK it is widespread in northern England, Northern Ireland, Scotland (including the Shetland Islands) and Wales. It is found at up to 600 m above sea level.
Overview: A tuberous perennial reaching up to 45 cm when in bloom, although usually less than 25 cm tall. Tubers (swollen, underground stem sections) are finger-shaped (as in all members of the genus Dactylorhiza).
Stems: Thick and hollow, developing in late March to early April (after a period of dormancy); mainly green but washed purple towards the tip.
Leaves: Mature plants have four to eight green, broadly lance-shaped leaves (sometimes with a purple tinged edge). Unlike several other species of Dactylorhiza, the leaves are generally unspotted. The lower leaves, which are the longest, are up to 16 cm long.
Flowers: The inflorescences (flowering stalks) are compact and crowded. They usually have 10–40 flowers, but can have up to 80.
The distinctive flowers are violet-purple with a paler throat, opening from mid May to late July, and are about 1.5–2.0 cm in diameter. The lip (the lower petal) is complex in shape and marked with deeper purple lines and spots. The lateral sepals are held at a 45° angle. The upper sepal and the petals form a loose hood over the column, which contains the sexual organs. The thick, downwards pointing spur is shorter than the purplish-green ovary.
Northern marsh orchids are commonly pollinated by bees, including bumblebees.
Northern marsh orchid is occasionally cultivated as an ornamental by a few orchid enthusiasts.
Millennium Seed Bank: Seed storage
The Millennium Seed Bank Partnership aims to save plant life worldwide, focusing on plants under threat and those of most use in the future. Seeds are dried, packaged and stored at a sub-zero temperature in our seed bank vault.
A collection of Dactylorhiza purpurella seeds is held in Kew’s Millennium Seed Bank based at Wakehurst in West Sussex.
Dactylorhiza purpurella should be grown in moist soil in sunny conditions. It performs best when grown outdoors, but at Kew it is also grown in containers under ambient temperatures for research purposes.
Commercial plants are not always available, but specialist orchid nurseries sometimes grow northern marsh orchid for sale using in-vitro culture.
This species at Kew
Dried and alcohol-preserved specimens of Dactylorhiza purpurella are held in Kew’s Herbarium, where they are available to visitors from around the world, by appointment. The details of some of these specimens can be seen online in Kew’s Herbarium Catalogue.
Kew’s research on marsh and spotted orchids
Dactylorhiza species (including marsh and spotted orchids) are the subject of research carried out by scientists in Kew’s Jodrell Laboratory, in particular with regard to population genetics.
Many species of Dactylorhiza are difficult to distinguish from each other, in part due to being highly variable. They are also subject to hybridisation and changes in chromosome numbers. Kew scientists and their partners use genetic data to differentiate between species and find out about their evolution. The results of these studies can be used to aid identification of Dactylorhiza orchids, which is an essential part of conservation projects.
Orchis purpurella T.Stephenson & T.A.Stephenson, Dactylorchis purpurella (T.Stephenson & T.A.Stephenson) Verm., Dactylorhiza majalis subsp. purpurella (T.Stephenson & T.A.Stephenson) D.M.Moore & Soó, Dactylorhiza majalis var. purpurella (T.Stephenson & T.A.Stephenson) R.M.Bateman & Denholm.
Baumann, H., Künkele, S. & Lorenz, R. (2006). Die Orchideen Europas. Weltbild, Augsburg.
Harrap A. & Harrap, S. (2005). Orchids of Britain & Ireland – A Field and Site Guide, 2nd Edition. A & C Black, London.
Inda, L. A., Pimentel, M. & Chase, M. W. (2010). Chalcone synthase variation and phylogenetic relationships in Dactylorhiza (Orchidaceae). Botanical Journal of the Linnean Society 163: 155–165.
Kretzschmar, H. (2008). Die Orchideen Deutschlands und Angrenzender Länder – Finden und Bestimmen. Quelle & Meyer, Wiebelsheim.
Paun, O., Bateman, R. M., Fay, M. F., Hedrén, M., Civeyrel, L. & Chase, M. W. (2010). Stable epigenetic effects impact adaptation in allopolyploid orchids (Dactylorhiza: Orchidaceae). Molecular Biology and Evolution 27: 2465–2473.
Paun, O., Bateman, R. M., Fay, M. F., Luna J. A., Moat, J., Hedrén, M. & Chase, M. W. (2011). Altered gene expression and ecological divergence in sibling allopolyploids of Dactylorhiza (Orchidaceae). BMC Evolutionary Biology 11: 113.
Pillon, Y., Fay, M. F., Hedrén, M., Devey, D. S., Shipunov, A., van der Bank, M., Bateman, R. M. & Chase, M. W. (2007). Evolution and temporal diversification of western European polyploid species complexes in Dactylorhiza (Orchidaceae). Taxon 56: 1185–1208.
Ryan, C. (2012). Cultivation of Dactylorhiza purpurella at RBG, Kew [interview] (personal communication, 10 May 2012).
Kew Science Editors: Rebecca Hilgenhof and André Schuiteman
Kew contributors: Mark Chase, Matti Niissalo
Copyediting: Emma Tredwell
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