Afrikaans name: Knapsekêrel
The Black-jack plant is native to North and South America and has been introduced to South Africa and many other countries. Most sock-wearing school kids will be familiar with the black seeds that easily catch onto socks if you brush past the plant. I spent a lot of time picking these seeds off my socks and other clothing during my younger days.
The Black-jack is an annual plant. It is scruffy looking and can grow to a height of 1.8 metres. It gets small white flowers which turn into clusters of seeds, each of which has barbs that enable them to catch on to clothing and fur. This is a very effective way for the plant to disperse its seeds.
In many countries the Black-jack is considered to be a medicinal herb while in others the plant is eaten. The leaves can be eaten raw or dried and eaten later, but care should be taken as some studies indicate that this could be a cause of oesophageal cancer. In parts of Africa, it is used to treat malaria. Apparently, a form of tea can be made from the tips of young shoots.
Seeds of Bidens pilosa
References and further readingA Field Guide to Wild Flowers in KwaZulu-Natal and the Eastern Region - Author: Elsa Pooley - Published: 2005 - Page: 218
Wild About Johannesburg - Author: Duncan Butchart - Published: 1995 - Page: 112