Gomphocarpus cancellatus is found in the winter rainfall area of southern Africa. It is especially common in the Western Cape where it is found as a pioneer along roadsides in disturbed areas. It is apparently rarer in the Northern Cape and Namibia.

After its introduction to Australia it became naturalised on roadsides and rocky hillsides in South Australia and Victoria, where it has become the larval food for the Wanderer butterfly. Because it has a fibrous root, it establishes itself easily and, because it can reach reproductive maturity within a year, members of this group can survive either as annuals, bi-annuals or perennials. The floriferous nature, combined with the abundance of pollinators and probably the ability to self-fertilise, ensure good seed set. Seeds are wind-distributed and establish easily in disturbed areas such as road verges.

The majority of taxa of this genus are short-lived perennial shrubs or subshrubs which behave as pioneers of open, disturbed habitats.

Bergtontelbos is attacked by plant lice and eaten by red locusts.

Like all asclepiads, the wild cotton also has an intricate mechanism of pollination. The pollinia, containing the pollen, are attached to the prospective pollinator's mouthparts when in search of nectar and carried to another flower. When the mature fruit bursts open, the coma fluffs out after drying to form a parachute carrying the seed. In the slightest breeze, the seeds are carried off and distributed by the wind.