fact: the irish yew is a variant on the common yew (taxus baccata), and most yew's in ireland today are derived from this yew discovered in 1760. its latin name is taxus baccata 'fastigiata' which means 'to grow upwards, hence its suitability and use in ornimental hedges and topiary.
both grow upwards, but the english spreads out ball like, instead of in a conical manner like the variant.

its use for bows stems from the fact that is is so elastic, it is hard and extremely durable. also, bowmen tipped their arrow heads with a poison made from the berry arils (stones), extremely poisonous, unlike the berry flesh, which is apparrently edible!