soda-apple nightshade

It is a shrub or small tree native to tropical Africa East to South Africa, in a wide range of soil, terrain, and climatic conditions. It is highly branched and reaches 1–5 m high, with numerous sharp, hooked, brown thorns. The leaves are ovate, up to 15 cm long and 13 cm broad, with lobed margins and downy undersides. It flowers (in South Africa) from September to July, peaking from November to March. The petals are white to pale violet surrounding the ovary, the flower also has a bitter, sour smell. These yield to fruit from April to January, peaking in June and November. These smooth, round berries are 6 cm in diameter and fade from green to yellow as they ripen. These berries contain high levels of the poisonous alkaloid solanine. The species name aculeastrum refers to the thorns that adorn most parts of the shrub.

Because of its dense growth and prickly nature, soda apple is used as a hedge and living barrier for containing livestock. It is often used as a soap replacement, as it is high in saponin. Traditional Zulu practices use the fruit - fresh, boiled, or charred - in herbal medicine to treat a wide variety of afflictions, including cancer, toothaches, and ringworm. The Taita tribe of southern Kenya use the ripe yellow fruit to treat paronychia. The roots are chewed and, the sap ingested to alleviate stomach aches.