First pic shows examples yet to ‘open’, the second some ‘open’ with a ‘groove’.
This collection was made July 13th 2014 just north of Newton Stewart NX4068 VC73 (first Scottish record?).
Unless someone wishes to make another suggestion I am inclined to record it as Hymenopsis typhae. Only 24 records in BMS database and 10 on CATE2 (mostly recorded by the Ellis family), neither has a record for Scotland (how fortuitous you mentioned the asco course)!