The fruit are smaller than a golf ball and green in colour, developing to yellow on maturity. The larger melons commonly seen on roadsides in rural Australia are in fact Citrullus lanatus, a wild relative of the watermelon.
These fruits are small, about the size of a golf ball, and green when they first grow. They change to yellow as they ripen. The large melons you see on Australian roadsides are actually Citrullus lanatus, a wild variety of watermelon.