Grewia occidentalis aka Crossberry

Grewia occidentalis is in the mallow family, Malvaceae. People call it crossberry and African starbush. It comes from southern tropical Africa and southern Africa. Its range spans South Africa, Botswana, Zimbabwe and Mozambique. It grows in dry scrub and on coastal dunes. It also grows in mountain forests and wooded grasslands. In closed forest, it may climb through other plants. At forest edges, it forms a shrub or small tree.

In gardens, it grows about 8–13 feet [2.5–4 metres] tall. Its spread is about 5–8 feet [1.5–2.5 metres]. The RHS says it takes 10–20 years to mature. Its thin branches can form a bush or scramble upwards. Sources differ on whether it keeps its leaves. The RHS says it stays green all year. Useful Tropical Plants calls it deciduous, meaning it sheds its leaves. Small groups of pink-purple flowers bloom in summer. Each star-shaped flower measures about 1.4 inches across. Fleshy fruits follow, each with four clear lobes. As they ripen, their yellow-orange skin turns purple.

Grow it in a sheltered spot with full sun. Useful Tropical Plants says it grows in shade too. The RHS calls for moist loam that drains well. For pots, it suggests peat-free compost with a loam base. The species can grow in a wider range of soils too. Once rooted well, plants can cope with drought. Reports differ on how much cold it can take. Useful Tropical Plants says it can bear some frost. The RHS rates it H2: it needs protection from freezing. Warm growing conditions free of frost are the safer choice.

It suits patio pots and can grow under glass. Its roots do not grow in an aggressive way. This lets you plant it near paving and buildings. It draws birds and butterflies to gardens. You may need to prune it to curb growth under glass. Sow seeds in spring at 16°C, or grow new plants by layering. The RHS reports few disease problems. Glasshouse whitefly and red spider mite may still attack it.

People eat the fruit raw and dry sweeter crops for storage. They also use ripe fruit to make beer. Useful Tropical Plants says people can eat the leaves too. It lists no known hazards, but this does not prove complete safety. The species has a history of use in traditional medicine. People use its wood for walking sticks, bows and spear shafts. They also use its bark in hair washes. Useful Tropical Plants gives its 2018 IUCN status as Least Concern.