Key facts
- Gaelic name: Mogairlean-bachlach bàn
- Height: Grows to around 30cm
- When in flower: July and August
- Species on the Edge areas: Outer Hebrides
Species information
How to identify
A spike of creamy white flowers, arranged in a small spiral atop an erect pale green stem. Grows to about 30cm high.
Distribution
Irish lady’s tresses is one of the rarest members of the orchid family in Europe, occurring only at scattered locations on the western seaboards of Ireland and Scotland and one site in England. It is absent from the rest of Europe.
It is actually one of a very small number of North American ‘amphi-atlantic’ species that found its way across the Atlantic. The species was first scientifically described on an expedition to islands off Alaska in the early 1800s and there are a number of theories as to how the plant may have made its way to our shores. The seeds are tiny and lightweight so might have been blown across the Atlantic or they could have been transported on the feet or feathers of birds blown off course on migration.
Life cycle
The life cycle of Irish lady’s tresses is still something of a mystery. Although its migration to the UK may have occurred as seeds, it has not actually been observed to set seed and it may be that some form of physical disruption of the roots, such as trampling by animals, is essential in its propagation. It also seems to have a complex life cycle so that botanists tend to find boom and bust periods for it, with flowering, vegetative and ‘underground’ phases over a cycle of seven years or so. In common with other orchids, a fungal associate is possibly crucial to the life cycle. The plant bears flowers in July and August. (credit RSPB)
Habitat
The habitat requirements of Irish lady’s tresses in its native home in North America are natural wetlands such as muskeg forest and beaver meadows, which will be subject to grazing by natural herbivore species such as elk and deer.
The sites where it has been recorded in Europe display a wide variety of conditions, within a broadly wetland habitat category. These include lake margins, peat bogs, rush pastures and unimproved wet grasslands. It appears to require good top-lighting and at least moderate soil fertility. A preference for seasonal inundation has been suggested, but the species does not favour permanently aquatic conditions. Importantly, such sites where it is found in Northern Ireland seem to be where traditional extensive grazing is still practised and so light grazing and rush cutting where needed may be key to keeping this beautiful little plant in our countryside. (credit RSPB)
Threats
Sine the 1950s, Irish lady’s tresses have been disappearing from many of its Scottish sites, possibly as a result of land use changes and loss of habitat. It is now confined to only a few sites.
What Species on the Edge is doing
Irish lady’s tresses is one of our target species in our Outer Hebrides project area. Conservation activity for the plant includes:
- Surveying and monitoring
- Producing a management advice document for Irish lady’s tresses
Gallery
