Reach for the sky

This is, without doubt, the biggest flower we have ever grown.  I say 'we' but frankly, we didn't have much input other than adding a bit of feed and water when required.  It's a Phormium, or New Zealand Flax, and we have three in the garden.  The plants have long pointed leaves and are themselves around six feet tall.  A couple of days ago I was surprised to see that this one had thrown up one flower spike whilst one of the others had produced three, seemingly overnight.  This one has now bloomed and having measured it, I can confirm that it is almost 10 feet (or just over three metres) tall, with a stalk of around two inches (around 5cms) diameter, whilst the other three are each around the same size.  I am just hoping that it isn't like the Mediterranean Agave plant that puts up a massive flower spike and then promptly dies of exhaustion!