<<Indeed. This goes so far that the German word for "clade" is _Monophylum_.>> I didn't know that but I know you must be correct, David! I've been living in Germany since 1992, and the German term I thought I'd noticed is 'Klad'.
It may be that someone once coined this out of despair, but if so, it hasn't spread very far. To me it sounds seriously awkward, as do all of the halfway obvious alternatives.
It leaves me wondering whether 'Kladogramme' should be written as 'Monophylogramme', but not seriously wondering and not for very long.
Well, there is _Kladistik_ and _kladistisch_, so... I don't see a problem here.