This shrub is often known colloquially as the butterfly bush, because of the shape of its flowers, which really do resemble beautiful blue butterflies. The Clerodendrum genus belongs to the broader Lamiaceae family of plants. Clerodendrum ugandense is a warm-climate plant which hails from tropical East Africa. It grows to about 2-3m tall and flowers in late summer and autumn. The charming flowers are not large so it is best to appreciate them at close quarters: they have several tones of blue on the 'wings' and the stamens look like the antennae of butterflies.
It grows best in sun (though will cope with part-shade), in reasonably fertile soil with adequate moisture. Like many warm-climate shrubs, it may look a bit untidy through winter, but it is best not to prune it until around the end of August. It grows fairly easily from cuttings taken in late summer and autumn. This shrub can become gangly and untidy after a few years, when it is probably best to replace it with a fresh specimen. It mixes easily into any colour scheme, but I enjoy it with a pale lemon Abutilon.
Note that this plant has now been renamed as Rotheca myricoides.
Postscript: in the end I tired of the straggliness of this shrub and removed it. I still think the flowers are delightful, however!