Friday, 4 September 2009

Common Fragrant Orchid

Common Fragrant Orchid (Gymnadenia conopsea)

Formerly the Common Fragrant Orchid, Marsh Fragrant Orchid and Heath Fragrant Orchid were classified together. They were then separated into three sub-species before their current recognition as three distinctly different species.

The species do align with the habitats indicated by their name grassland in the case of the Common Fragrant Orchid, and marsh and health land in the case of Marsh and Heath Fragrant Orchids. However these habitats can overlap so details of the features of plants must be used. While there are differences between minimum and maximum heights of plants this is not an ideal defining character to use because their height ranges overlap. The characteristic I have found most useful is the differences in form of the lower lip of the flower. Look at this feature on several different plants in a colony to make sure that you are not using the one odd one in a group. There is some additional complexity in identification because Fragrant Orchids readily hybridise with each other leading to intermediates which are hard to identify because of similarity and because the defined identification characteristics are still being developed for these species.

Common Fragrant Orchid is found mainly on dry unimproved grassland on calcareous soils. It requires some grazing of the grassland to limit the development of scrub, but intensive grazing does not support this species so maintenance of its habitat is a fine balance.

It flowers from mid May to late July and the flowers occur in shades of pink from a near purple pink through to pale pink and with white varieties present too.

I scrabbled around the top of the North Downs above Wye and found a couple of single tatty plants. Heading straight down the steep slope crossed by terracettes I found hundreds of Common Fragrant Orchids. It was a still sunny day and the fragrance rose up from the flowers so strongly there was not need to stoop to smell them.


Anonymous said...

Im struggling to identify the differences between the three types. Im relying on the guide book when visiting a site that only one type of fragrant orchid occurs at but at a site like Waitby Greenriggs near Kirkby Stephen where all three occur its difficult. I guess it will come with practice.


Susanne said...

I find the differences between lip and lateral sepals very useful to distinguish between them. If you are finding mixed key characteristics it is possible you are looking at a hybrid. Having them all on one site can make it easier to see the differences that the books are talking about. There is a handy quick guide here