Peter Smith writes as follows.

On one of those March afternoons with bright sunshine but a cold wind, a group of members followed a loop along the Grand Union Canal and the meadows of the River Sence, taking in the charming churches of Newton Harcourt and Wistow.  Our guide was Ivan Pedley, who was keen to share his enthusiasm and deep knowledge of lichens and much else besides!  In the churchyard of St Luke’s, we noted how the limestone gravestones were heavily encrusted with lichens, compared with the few that will grow on the more acid slate.  It was also clear on the roof and below the nameplates on certain memorials how the run-off from lead, copper and zinc suppresses the growth of all but a few tolerant lichen species.

A limestone gravestone covered in lichens (mostly Verrucaria species) (Photo: Peter Smith)

As in most of our region, the trees and hedges along the canal towpath were densely covered with lichens that thrive on high levels of nitrogen from agricultural fertilizers and vehicle emissions: the vivid orange of the Sunburst Lichen (Xanthoria parietina) on Blackthorn twigs and a mosaic of Lecidella eleachroma and Lecanora chlarotera on the smooth bark of Ash.

Xanthoria elegans, which has survived in outer space! (Photo: Peter Smith)

At Wistow, we learned the sad story of St Wistan, before Ivan showed us species that we share with some of the most extreme environments on the planet: Lecanora polytropa has been found on Himalayan summits and Xanthoria elegans has survived for 18 months in an experiment on the outside of the International Space Station.

Sweet violet (Viola odorata var. dumetorum) (Photo: Peter Smith)

Aside from lichens, the churchyard at Newton Harcourt was full of a demure Narcissus, which appeared to be the native species N. pseudonarcissus (presumably introduced).  There were Sweet Violets (Viola odorata) by the canal, including some white ones which our two County Recorders identified as the variety dumetorum.  Blackcap and Yellowhammer were singing early in the year.  Few insects were active in the cold weather but your reporter noted a queen Buff-tailed Bumblebee (Bombus terrestris) searching for a nest site and recorded the small, four-spotted ground beetle Bembidion quadrimaculatum among the ants on one of the church walls.

The beetle Bembidion quadrimaculatus (photo: Peter Smith)

A full report will be published in the next newsletter, which is available to members.

(Photo at top: Peter Smith)