Australian Tropical Rainforest Plants - Online edition

Commelina diffusa Burm.f.

Herb (herbaceous or woody, under 1 m tall)
Click/tap on images to enlarge
Flowers. © G. Sankowsky
Habit, leaves and flower. © G. Sankowsky
Herbarium specimen. © CSIRO

Burman, N.L. (1768) Fl. Ind. : 18, t.7, f.2.

Common name

Scurvy Weed


Sprawling fleshy herb with ascending branches up to 75 cm tall, rooting at the nodes.


Leaf blades about 20-35 x 7-9 mm. Leaf surface can be either glabrous (i.e. hairless) or hispid (i.e. bristly), subsessile and hispid.


Inflorescence enclosing bracts green. Inner perianth segments pale to bright blue Lower cincinnus with 2-4 flowers, upper cincinnus with 1- several flowers. Upper cincinnus bears only male flowers and has a longer peduncle, while the lower cincinnus bears bisexual flowers on a shorter peduncle. The pedicels are thick and curved and 3-5 mm. The membranous sepals are inconspicuous, 3-4 mm ilong. The upper two petals are 4.2-6 mm. The anther connective (i.e. the tissue connecting the two halves of the anther) of the centre-most stamen has a broad transverse band of violet. The spathes solitary, borne on a peduncle and typically falcate with a cordate to rounded base, acuminate apices and can be either glabrous or hispidulous beneath, 0.8-2.5 cm long, but may be as short as 0.5 cm and as long as 4 cm. Peduncles 0.5-2 cm long.


The fruit has three locules and 2 valves, 4-6.3 x 3-4 mm and contain five seeds. Seeds brown, 2-2.8(-3.2) x 1.4-1.8 mm, testa deeply reticulate.


Features not available.

Distribution and Ecology

Occurs in NT, CYP, NEQ, CEQ and southwards to southern New South Wales. Altitudinal range from sea level to 1090 m. Occurs in a wide range of vegetation types from rainforest to wooded grassland. Also occurs in tropical Asia eastwards to Polynesia, including Hawaii.

Natural History & Notes

Juice being used to cure wounds, for inflamed eyes, as part of an external remedy for bone fracture and as a digestive aid (Smith 1979).

Women rub their hair with it in the Torres Strait area (Lawrie s.n.)

Within China it is used as a medicinal herb with febrifugal and diuretic properties. A dye is also obtained from the juice of the petals for use in painting.

RFK Code
Copyright © CSIRO 2020, all rights reserved.