Medicinal Plant Images

Figure 1: Petalostigma triloculare (commonly known as quinine bush) tree. Petalostigma is an Australian Euphorbiaceae genus which consists of 7 species. They grow to between 2 and 10 metres in height and have bright orange fruit (when ripe). Petalostigma species were used extensively by indigenous Australians to treat a myriad of bacterial, fungal and viral diseases.1 Petalostigma pubescens and P. triloculare bark and fruit decoctions were used extensively by Australian Aborigines as an antiseptic and to treat sore eyes. Fruit were also held in the mouth to relieve a toothache.1 Despite its common name, there is no scientific evidence to support the presence of quinine in the fruit or leaves (the common name is presumably due to the extremely sharp bitter flavour of the fruit). Recent studies have confirmed the antibacterial, antifungal and antiviral activity of extracts of the leaves and fruit of this plant.2,3 Additionally, a recent study also reported that Petralostigma spp. Extracts also potentiated the activity of some conventional antibiotics, even against bacterial that are otherwise resistant to those antibiotics.4 This photograph was taken at Griffith University, Brisbane, 2026 by Dr. Ian Cock. Figure 2: Australian Acacia spp. The genus Acacia (family Fabaceae) is a large genus of more than 1200 trees and shrubs which are widely distributed throughout the world, with more than 700 species indigenous to Australia. The Australian species had multiple medicinal uses by indigenous Australians, including being used to treat diarrhoea and hyperglycemia,1,5 and as a general antiseptic agent.6-10 Many Australian Acacia species have been reported to have amtimicrobial, molluskicidal, antihypertensive and platelet aggregatory activities.1 This photograph was taken in Brisbane, Australia, in 2026 by Dr. Ian Cock.