Fall Flowers. Blackwood (Peltophorum africanum). Semi-deciduous to deciduous trees of about 15m with a spreading, untidy canopy, originated from Southern Africa. There are various medicinal uses recorded for this plant. Roots are used to heal wounds, toothache and throat sores; root, leaves and bark used to clear intestinal parasites and relieve stomach problems; bark relieves colic; stem and root used for diarrhoea and dysentery.