Sunday 6 May 2012

Super-species ?



On finding an orchid with green lines on the side petals in Britain you would be fairly confident that it is a Green-winged orchid (Anacamptis morio). However once you reach mainland Europe and head south identifying the flowers pictured above becomes more difficult. The main guide to European, north African and Middle Eastern orchids (Delforge 2005) groups together 4 possible species; morio, picta, champagneuxi, and longicornu, in a species complex.

I found the flowers pictured here in Turkey and it is likely that they are Green-winged orchids that are slightly spindly in their growth because they are growing in partial shade. With characteristics such as stature and leaf size being influenced by growing conditions the main ways to differentiate the four species are the dimensions of the different sections of the flowers. Delforge adds that A. morio show more colour variation than A. picta.  The group of orchids I found had a lot of colour variation ranging from almost white to dark pink-purple flowers; but that does not in itself mean that they are A. morio.  

Sometimes when plants are not easily distinguished the right question to ask is not what species specific plants are but are all these species really separate species? A few emailed conversations asking about confirming identification as a Green-winged orchid led one person to suggest that sampling across Europe would be likely to find that the four species are in fact one super-species – with characteristics that vary on a continuum rather than characteristics that can be separated.