This has a similar appearance to Cuphophyllus virgineus but as the specific name indicates, it has a strong smell of Russian leather. It is often encountered in sizeable groups. Like many waxcaps it prefers unimproved grassland and is happy in acidic and alkaline substrates.

References: 
Boertmann, D. (2010 revised second edition) The Genus Hygrocybe
Harries, D. (2017) A Guide to Waxcaps in West Wales
Bessette, A.E. et al. (2012) Waxcap Mushrooms of Eastern North America