A new and interesting site for the Calcite-encrusted desmid Oocardium stratum Naeg. in the British Isles

Oocardium stratum has been discovered growing within a protruberant mass of crystalline travertine (“cron”) developing below a small spring near Cam Gill in the Yorkshire Dales. The site is described and compared with two others, one in nearby Gordale Beck and the other at Lahage, Belgium. Although the physical and chemical characteristics of two sites (Cam Gill and Lahage) are similar, there are few algae common to both. Cam Gill cron contains the best example of Oocardium travertine so far discovered in Britain. Oocardium growth rate at the new site is about 1 mm y^-1.