A botanical pilgrimage...

I spent a very hot and sweaty day surveying areas of mosquito-ridden alder woodland and tangled swampy vegetation, with some rather species-poor semi-improved grassland thrown in. At one point I had to cross a chalk stream on a very precarious looking arrangement of planks - I had to hand the camera to Pete as the throught of dropping it in the water had me paralysed with fear!

We finally finished about 4.30pm, which would have meant travelling up the A14 during rush-hour - we'd already had enough of sitting in traffic jams on our morning journey. So, to fill in some time we decided to walk a section of the Devil's Dyke, a 12.1 km Anglo-saxon earthwork which supports some of the finest chalk grassland in Cambridgeshire.

I've had a long involvement with the Devil's Dyke, as it was one of my SSSIs when I was a Conservation Officer with Natural England, and one of my first jobs as a self-employed ecologist was undertaking an NVC survey of the whole site. I hadn't visited for some time, so it was good to see that the grassland was looking in fine condition, with all the expected plants. We also saw the first chalkhill blues of the year and a couple of dark-green fritillaries, recently re-established.

But the main attraction for me was the population of lizard orchids. Despite living relatively nearby for almost thirty years, I'd never been to see them flower. As a young conservation officer in the late 1980's I'd helped to count the leaf rosettes of this rare and protected species on a bitterly cold and frosty autumn day. At that time numbers were small, and the local wildlife trust had a warden to protect them during the flowering season. Today there was no warden, but the grassland management had clearly paid dividends as we counted 141 flower spikes (and I'm sure we missed a few).

This very large and impressive orchid has flower spikes up to 70cm in height. The flowers have petals and sepals that form the head, and divided lips that look like the legs and long twisting tail of a lizard. The flowers are mostly pale and greenish, with delicate pink spots and stripes - this specimen was one of the most dramatically coloured. As the flower bud opens the lip uncurls like a watch spring, and twists as it unrolls. It is said to smell strongly of goats, though this wasn't very noticeable in the stiff breeze.

This species is restricted to the southern half of England. There has been an expansion in its range since 1990, but the main populations are still in east Kent, Cambridgeshire and Suffolk, always on chalk grassland. It's thought that it may be benefiting from the warmer, wetter winters of recent years.

Probably worth looking at under the magnifying glass!