Carissa spinarum aka Egyptian Carissa

Carissa spinarum, or carrisse, belongs to the Apocynaceae family. It is an evergreen shrub that can form a small tree. Kew places its native range from southern New Guinea to northern Queensland, including the Aru Islands. Useful Tropical Plants gives a broader tropical and subtropical range. Its account extends from Africa through Asia to Australia and New Caledonia.

The plant forms many branches and sometimes scrambles through nearby growth. The listed garden height is about 13 feet [4 metres]. The fuller account gives heights of 3–18 feet [1–5.5 metres]. Dark grey bark bears straight, woody spines, often in pairs. These can reach about 0.16 feet [0.05 metres] long. The bark also contains white latex. Its evergreen growth and flowers give it value as an ornamental.

Flowers may be white or purple and appear through much of the year. Bees visit them, and fruiting can also span many months. The fruits often grow in pairs. They turn from red-black to blue-black as they ripen. Each measures about 0.05 feet [0.015 metres] across. People eat the sweet fruit fresh or cook it into jam. They also ferment it to make vinegar. Local people gather the plant for both food and medicine.

Grow it in full sun with soil that drains well. It prefers deep, fertile ground but also grows in sandy or rocky soil. Wetter ground promotes leafy growth at the expense of fruit. The reported preferred soil pH is 6.5–7.5. It tolerates a wider range of 6–8. This is a plant of hot, often dry climates. Reported habitats include dry forest, coastal thickets, savannah woodland, and disturbed ground. Seeds and cuttings offer easy ways to raise new plants. Air layering is another recorded method.

The roots have traditional uses as flavouring for water, soups, and stews. They also feature in remedies for worms and other ailments. These records describe traditional use, not proof of safe treatment. People use the fruit for tannins and dyeing. The hard wood supplies spoons, combs, other small items, and fuel. Root preparations have also served as fly repellents. Useful Tropical Plants lists no known hazards. That statement does not establish safety for every plant part or use.