Carissa carandas aka Karaunda

Carissa carandas is a woody shrub or small tree. It belongs to the Apocynaceae family. Its native range covers India and southeastern Bangladesh. Gardeners may know it as karanda or Christ's thorn. It grows in tropical and subtropical regions with seasonal dry spells. Reports from Nepal place it on dry, sunny sites. There, it grows at heights up to 3,280 feet [1,000 metres].

The plant can climb and reaches 10–16 feet [3–5 metres]. One reference also gives a height of 13 feet [4 metres]. Sharp spines grow along its stems. These may be simple or branched. The plant contains white latex. Gardeners grow it for both fruit and its looks. Its fruit display gives it value in warm-climate gardens. It remains more of a garden crop than a commercial one.

Flowers can appear at any time of year. The fruits are round to broadly egg-shaped. They turn purple to near-black and measure 0.03–0.08 feet [0.01–0.025 metres] long. The fruit tastes very sour before it becomes fully ripe. Full ripeness brings some sweetness, though a sour taste remains. People eat it raw or cook it with sugar. In Thailand, cooks use it mainly for pickles. It also goes into jam, jelly, puddings, drinks, curries, and tarts.

Grow karanda in full sun or light, broken shade. It grows best with daytime temperatures of 23–30°C. The cited range it can tolerate is 16–34°C. Temperatures of −2°C or below may kill it. Reported preferred yearly rainfall is 1,000–1,400 millimetres. The wider reported range is 700–2,700 millimetres. Soil guidance varies between sources. One favours moderately acid soil; another gives a preferred pH of 6.5–8. That source reports tolerance from pH 6 to 8.5. Seed-grown plants take about three years to start fruiting. Plants raised from cuttings may fruit within one to three years. Cuttings and air layering can be hard to establish.

Traditional uses include fruit remedies and preparations from leaves and roots. These records describe uses, not proof that treatments work. People also use the roots to repel insects. The hard wood serves for small tools, household furniture, and turned objects. The source lists no known hazards, but this does not establish safety for every use. Take care around the sharp stem spines when handling the plant.