What is this African shrub with spikes of brilliant blue flowers?

Question

A friend of mine is currently abroad in Africa, and she took this photo of a brilliantly-colored flower in Malawi:

I'd love to have something at home so brilliant, but obviously I have no idea what it is. My first thought was of some kind of lupine, but the gradual shift from brilliant blue to muted pink and the shape of the petals seemed uncharacteristic of any of the lupinus flowers I've seen.

The only other information I can provide is that this was taken somewhere near Dedza, in Africa, and that it appears to just be the flowering tip of a larger plant or tree.

Answer 1

I believe I've found it:

Pycnostachys urticifolia, more commonly called Blue Witches Hat.

From Annie's Annuals:

Stunning, bright cobalt blue, “Witch’s Hat” blooms delight us Fall through early Spring on this easy-to-grow, evergreen perennial/shrub from South Africa. Fast growing to 4’ or 5’ tall & almost as wide, it creates a multi-branching shrub, eventually forming quite a solid, woody, main trunk.