This seems like a trivial problem, but I can\'t figure it out.
On Bootstraps own website they have the Select example.
the class is called:
.form-control { border-radius: 0; }
be sure to insert the override after including bootstraps css.
If you ONLY want to remove the radius on select form-controls use
select.form-control { ... }
instead
EDIT: works for me on chrome, firefox, opera, and safari, IE9+ (all running on linux/safari & IE on playonlinux)