Introduced annual forb or climber with a perennial rootstock, prostrate or to 3m tall. Leaves alternating along the stems, 2-10cm long, 20-70mm wide, flat, rough, lobed, with wavy edges. Male and female flowers on the same plant. Flowers yellow or greenish yellow, with 5 petals, borne singly on short stalks arising from the bases of the leaves. Fruit dark green mottled or striped with yellow, or yellow.
The melons differ from those of Citrullus lanatus in that the melons are always spherical, the flesh is very bitter, and the mature seeds yellow or dull yellow-brown.
Description in G.M. Cunningham, WE Mulham, PL Milthorpe and J H Leigh (1981 and later printings) Plants of Western New South Wales page 624