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|Western marsh orchid (Dactylorhiza majalis)|
(Rchb.) P.F. Hunt & Summerh.
Orchis majalis Rchb.
Dactylorhiza majalis (western marsh orchid, broad-leaved marsh orchid, fan orchid, common marsh orchid, or Irish Marsh-orchid) is a terrestrial European orchid. Its flowering period begins at lower elevations as early as the beginning of May and ends in higher elevations at the end of July. The lowest blossoms usually open even before the stem has reached its full height.
The western marsh orchid is usually 15 to 40 cm (6 to 16 in.) tall, though some specimens may reach 60 cm (2 ft). Three to eight dark spotted leaves are distributed on the stem, which is hollow. The lower leaves are ovate to lanceolate and 6 to 18 cm (2⅜ to 7 in.) long and 1.5 to 3.5 cm (⅝ to 1⅜ in.) wide. The upper leaves are increasingly smaller and more lanceolate. The bracts are about as long as the blossom and cover it before it blooms. The densely flowered inflorescence, which is 4 to 15 cm (1½ to 6 in.) long, is at first conical, but distinctly cylindrical when in full blossom. The seven to forty blossoms are colored purplish red, rarely light pink or white. The lateral tepals of the external circle of the perianth stand obliquely or vertically upright. They are 7 to 12 mm (¼ to ½ in.) long and 2.5 to 5 mm (⅛ to 3⁄16 in.) wide. The middle tepal is smaller and forms a "helmet" together with the two lateral tepals of the internal circle. These are 6 to 11 mm (¼ to 7⁄16 in.) long. The trilobate lip is 5 to 10 mm (3⁄16 to ⅜ in.) long and 7 to 14 mm (¼ to 9⁄16 in.) wide. The shape and pattern of the lips are variable. In the lighter central area of the lip the markings are made up of lines, streaks, or dots. The spur is bent slightly downwards and is not quite as long as the ovary. The tuber has a palmate division and an irregular shape.
The western marsh orchid has a karyotype of two sets of forty chromosomes. The seed of this orchid contains no endosperm for the embryo. Therefore, germination can take place only by means of infection with a root fungus (mycorrhiza).
In Germany the western marsh orchid is widespread but with several gaps. In many places, especially from western to northern Germany, it is extinct.
Conservation and endangerment
Although the western marsh orchid is commonly found in some regions, it is nevertheless protected as an orchid.
As with many marsh plants, the numbers of this species have been dwindling for quite some time. The main causes are the entry of nitrogen via fertilizer, drying out of the habitat, and intensive conversion to pasture. The western marsh orchid does not react so sensitively to changes in its habitat as for example the early marsh orchid. It is usually the last of the native orchids to disappear. This tolerance makes it a still relatively common species.
Varieties and hybrids
- Dactylorhiza majalis var. pumila (Synonym: Dactylorhiza majalis var. alpestris), an Alpine variety.
- The western marsh orchid hybridizes quite commonly with other species of its genus.
- Dactylorhiza × aschersoniana (incarnata × majalis)
- Dactylorhiza × braunii (fuchsii × majalis)
- Dactylorhiza × dufftiana (majalis × traunsteineri)
- Dactylorhiza × godferyana (majalis × praetermissa)
- Dactylorhiza × kuehnensis (majalis × ruthei
- Dactylorhiza × townsendiana (maculata × majalis)
- Dactylorhiza × rupertii (majalis × sambucina)
- More rarely hybrids with other genera (intergeneric hybrids) occur.
- ×Dactyloglossum drucei (Coeloglossum viride ×Dactylorhiza majalis)
- ×Dactylodenia lebrunii (Dactylorhiza majalis × Gymnadenia conopsea)
In 1828 Ludwig Reichenbach described the western marsh orchid as Orchis majalis. The name became the basionym after Peter Francis Hunt and Victor Samuel Summerhayes transferred the species to the genus Dactylorhiza in 1965. Sometimes the name Dactylorhiza fistulosa is used, but since this description is not valid, the name cannot be used despite its earlier publication in 1794 as Orchis fistulosa.
- Orchis majalis Rchb. 1828 (basionym)
- Dactylorchis majalis (Rchb.) Verm. 1947
- Dactylorhiza comosa ssp. majalis (Rchb.) P.D. Sell & G.Murrell 1996
- Orchis fistulosa Moench 1794 nom. illeg.
- Dactylorhiza fistulosa (Moench) H. Baumann & Künkele 1983 nom. illeg.
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