I have had this blue cactus for years growing in a large pot. It is now about three metres tall and shows no sign of stopping growing .The roots have come away from the base of the pot and are spreading in all directions. For the first time it has produced a single flower which just appeared as a purple fig-like funnel shaped object projecting from the trunk. Around its base there are tufts of what looks like fur. The flower opened last night but was still open this morning to be captured by the camera. Pilosocereus cactus are native to Brazil and threatened with extinction in the wild due to habitat loss.