A survey by the Cambridge Lichen Group, 9th April 2017 Mark Powell, Louise Bacon, Catherine Tregaskes, Paula Shipway
Seventy-six taxa were recorded from various habitats at Roswell Pits. Three of these are lichenicolous fungi; an under-recorded group of organisms that infect lichens. One of these, Pyrenochaeta xanthoriae was added to the British list in May 2016 and the occurrence at Roswell Pits is new to Cambridgeshire and the third record for Britain.
The most notable lichen community occurs on the trunks of old stubby trees on the bank beside Springhead Lane. A particularly notable example of this community occurs at TL5521.8050 where Bacidia viridifarinosa forms extensive pale green sorediate patches at the bases of the trunks. B. viridifarinosa is known from just one other site in Cambridgeshire, in Madingley Wood.