Cucumis metuliferus aka African Horned Cucumber

Cucumis metuliferus is an annual vine in the cucumber family, Cucurbitaceae. Its names include horned melon, jelly melon, and kiwano. It comes from tropical and southern Africa and the southwestern Arabian Peninsula. Its native climate has warm conditions and a dry season. Gardeners grow it for its fruit in beds or under glass. It can climb or scramble, rather than form an upright bush.

The RHS describes a vine reaching about 8 feet [2.5 metres]. Its listed garden height range extends to 13 feet [4 metres]. The spread is about 0.3–1.6 feet [0.1–0.5 metres]. It reaches its full size within one year. Green leaves have lobed edges, and the plant sheds its foliage. Yellow flowers lead to horned fruit about the size of an egg. The skin turns golden yellow as the fruit ripens. Inside, green flesh surrounds green seeds. The horns and bright skin give the crop a striking look.

Give this plant full sun and a warm, sheltered site. The RHS recommends loam that stays moist but drains well. It accepts acid, neutral, or alkaline soil. A greenhouse or conservatory offers another place to grow it. The RHS rates it H1C, suited to summer growing outdoors in Britain. That rating covers minimum temperatures of 41–50°F [5–10°C]. Plants For A Future lists USDA zones 9–11. Raise new plants from seed; the RHS says no pruning is needed.

The fruit and seeds can be eaten raw. The leaves are eaten cooked. Reports differ on the fruit's taste, from bland or bitter to banana and lime. The small seeds have a nutty taste and contain oil. Their fibrous coats make them awkward to prepare. Food uses do not mean every part is safe. Sprouting seeds produce a toxic substance in the embryo. Bitter fruit can also poison pets. Plants For A Future records a traditional seed treatment for intestinal worms.

Glasshouse red spider mites and whiteflies may attack the plant. Powdery mildew and cucumber mosaic virus can also cause trouble. Growers have used it as a cucumber rootstock to improve disease resistance. Its lower cold tolerance limits that role in cool temperate areas. Plants For A Future does not flag it as weedy.