Tuesday, 3 May 2011

Coastal Orchids

The seaside might not be the first place you think about as a place to see orchids but it is a great location for a variety of orchids including several of the less common species. I’m inspired to think about coast orchids at the moment as Roddy Jenkins is walking the South West coast path to raise money for the National Eczema Society http://www.justgiving.com/Roddy-Jenkins On his journey from Minehead in Somerset to Poole in Dorset over the next few weeks the path will take him past Early-purple and Green-winged orchids in bloom. He might spot the rogue colony of Serapias that are reputed to be found on the Devon/Cornwall border.

Thinking about orchids in Britain they tend to be associated with thoughts of cool lush meadows and woodlands. However many tuberous orchids are well suited to coastal conditions where fresh water can be limited and winds are strong. The tubers of some orchids including Early-purple, Green-winged and Lizard orchids contain glucomannan – a molecule that retains water and lowers freezing point. These two properties provide drought tolerance and frost resistance to plants .With the bulk of leaves in basal rosettes the drying effects of wind are also reduced.

Coastal locations offer a range of different habitats. Dune slacks, the hollows between dunes, can provide damp or marshy conditions where groundwater level is above the soil level. Dune slacks are a great location for Marsh helleborines. Steep slopes where the soil is a thin layer over chalk and the land is grazed are where I have found Autumn Lady’s-tresses. Dune helleborines, as indicated in the name are found in sandy soils. One rainy day in Lancashire I spotted their distinctive sickly green leaves under pine trees on the Lancashire coast. It was too rainy to get a photo of the opening flowers but living in the south I was delighted to see a plant that has a northerly distribution. On the north coast of Scotland I found Twayblades running through the sand dunes flowering in August; when the first Twayblade I had seen that year was open in May in the south.

So while there is plenty to keep me busy on or in the water getting down to the shore it is always worth looking out for the plants that grow on the coastal cliffs and sand dunes.


Peter Chilton said...

Hi Susanne,
on sunday 27/5 i will be walking the coast to coast for two weeks are there any orchids i should keep a watch out for and their locations if you know them

thanks Peter

Susanne said...

Hi Peter,

Is that Wainwright's coast to coast? Bit chillier up north so probably just Early Purple Orchids out - but they are widespread and often abundant so you could see lots. They can be on grassland or in woods. Near the coast on grassland you might see Green-winged Orchids. On grassland it is worth taking a closer look if you see a yellow blur of cowslips; good sign of unimproved pasture which both Green-winged and Early Purples do better in.