In 2017, Tom Blockeel published an article which explained why the species known as U. crispa in Smith’s 2008 moss flora appeared to be ill-defined and readily confused with U. bruchii. Since that then, British and Irish bryologists have slowly been getting to grips with the three species that U. crispa s.l. became – U. intermedia, U. crispula and U. crispa s.str. The Ulota intermedia page compares the 3 species and gives some hints on how to examine peristome characters.
U. crispa is a mid-season species and the best time to search for and identify it is when its strongly contracted capsules mature in mid-late summer.
For lots more useful information, Tom’s article is strongly recommended and you can download a PDF by following the link at the bottom of this page.Read the Field Guide account