Before the Battle of Agincourt in 1415, the French, hugely outnumbering and thus confident of victory over the English, proposed to cut off the middle finger of all English soldiers captured in the conflict. Without the middle finger it would be impossible to draw the renowned English longbow and as such, the archers would be useless for any future fighting. This famous longbow was made of the native English Yew tree and the act of drawing the longbow in medieval times was known as 'plucking the yew' (or, 'to pluck yew'). Much to their bewilderment the French were soundly thrashed in battle by the English who then took great delight in mocking the defeated frogs by waving their middle finger and proudly proclaiming "See, we can still pluck yew!" The wearing of a leather & chainmail archer's helmet made the statement of "Pluck Yew" rather awkward and clumsy to enunciate so as a consequence, the difficult consonent cluster at the beginning gradually evolved to a labiodentials-fricative 'F'. Nonetheless the words were still used in conjunction with the one-finger-salute and (particularily in the British colonies of Canada and New Zealand) it remains to this very day an APPROPRIATE SALUTE TO THE FRENCH! It is also in recognition of the pheasant feathers on the arrow fletching that the symbolic gesture is commonly known as "flicking the bird". Here endeth the lesson. So, until now, yew probably thought yew knew every plucking thing!