Had this experience a few times now. I (e)xamine a mutated poppy flower, select y to pick a flower. And the game becomes unresponsive.
No idea why. I do know I once got a poppy flower bud and some other object. So perhaps it crashes when the searching comes up empty.
I have a copy of a save file near a flower if that helps. (And I’m running windows, the Cataclysm DDA Version 0.2 release).