Blackjack

About: Blackjack (Bidens pilosa) is a fast-growing annual herb or weed native to the Americas but now widespread across Africa, Asia, and tropical parts of the world. Though often cursed for its sticky seeds that cling to clothes, it has long been used as a wild vegetable, traditional medicine, and even livestock fodder. In Southern Africa, blackjack leaves are eaten like spinach, and the plant is rich in minerals and vitamins, especially iron and calcium.

Identification: Blackjack has upright, branched stems that are green or reddish and often ribbed. The leaves are green and divided into three to five pointed lobes, with serrated (toothed) edges. The flowers are small and daisy-like, with a yellow disc centre and 3–5 small white petals, sometimes barely visible. After flowering, the plant produces narrow, black seeds with two barbed spines that easily attach to fabric, fur, and skin — a key identifying feature.

Habitat: Blackjack is widespread in disturbed soils, gardens, roadsides, crop fields, and waste places. It grows especially well in sunny areas with loose or cultivated soil, but can also be found in shaded locations. In South Africa, it grows across all provinces and is especially common during the summer rainfall season. The plant germinates rapidly after rain and can mature within a few weeks, making it one of the most persistent weeds in cultivated land.

Uses: Blackjack is a highly nutritious wild vegetable, rich in vitamin C, vitamin A, calcium, magnesium, and antioxidants. The young leaves and shoots are commonly cooked and eaten as a green vegetable, often boiled and served with maize porridge (pap) or added to soups. The leaves have a slightly bitter taste that reduces with cooking. In traditional medicine, blackjack is used to treat a range of conditions, including mouth infections, wounds, digestive issues, colds, and skin problems. Leaf juice is sometimes applied directly to cuts or sores, and infusions are drunk for coughs and stomach complaints. Scientific studies have confirmed the plant's antibacterial and anti-inflammatory activity, supporting some of its traditional uses.

Harvesting Tips: Harvest young leaves and tender shoots before the plant flowers, as older leaves become tougher and more bitter. Use clean scissors or pinch off the tops of the plants. Avoid plants growing near roadsides or polluted areas, as blackjack easily absorbs contaminants from the soil. To avoid spreading the plant accidentally, take care not to drop the seeds, and clean clothing and bags after harvesting. For medicinal use, fresh leaves are typically used immediately, but they can also be dried and stored in a clean, dry place for later use.

Fun Fact: The sticky seeds of blackjack are perfectly designed to hitch a ride on your clothes, socks, or animal fur — each seed has tiny barbs that act like Velcro! In fact, their design inspired early research into hook-and-loop fasteners (yep, Velcro was literally inspired by plants like this one).