Orchids, Darwin and a Pencil

Some years ago I bought a pot of orchids at a plant sale. There was no label so I am not sure of the identification but it is possibly Dactylorhiza foliosa which is native to Madeira. They are similar to our native early purple orchid but much bigger and look spectacular. They have flowered reliably ever since even surviving the very cold winter of 2010 to 2011.

The pollination of these orchids is quite unusual in that the pollen grains are contained in a pollinium. (This is a single stem like structure containing a mass of pollen, the male part of the flower, at its tip. It is usually glued to an insects head or proboscis as it visits the flower. Once the insect leaves the flower the pollinium actively bends so when the insect visits the next flower the pollen is transferred onto the stigma, the female part of the flower.)

Darwin studied orchids in detail and in 1862, published  a book on the 'Ferilisation of Orchids'.  He carried out one experiment using a pencil to extract the pollinium. I wasn't sure whether I could repeat it on my pot of orchids but much to my surprise when I pushed the tip of a pencil into one of the flowers there was the pollinium.

Pollinium attached to the pencil tip.