Hibiscus diversifolius aka Cape Hibiscus

Hibiscus diversifolius also goes by the name swamp hibiscus. It belongs to the mallow family, Malvaceae. It comes from tropical Africa but now grows across the tropics. People have helped spread it beyond its home range. It grows by rivers and in swamps with open plant cover. In eastern Australia, it also grows near rainforests along the coast. Some plants grow on disturbed ground or in very wet sites.

This shrub has spines and sheds its leaves. Its woody stems can give it a small tree's form. Sources give quite different sizes for this plant. PFAF lists a garden height of about 3 feet [1 metre]. It gives a spread of about 2 feet [0.6 metres]. Useful Tropical Plants gives heights of about 10 feet [3 metres]. That source also lists 16 feet [5 metres] in height. Rare plants may reach 33 feet [10 metres]. Leaves change shape as the plant grows. The first leaves have a half-round shape. Later leaves have three clear lobes, or sections.

People grow swamp hibiscus for its looks and sometimes for food. Insects pollinate the flowers. Each flower has both male and female organs. The plant is self-fertile: it can set seed on its own. In temperate areas, gardeners can grow it as an annual. It can bloom and set seed in its first year. The supplied sources do not state when it blooms. They give no flower colour or fruit form for this species.

Grow it in full sun with moist, rich soil. It prefers soil rich in humus that drains well. It accepts sand, loam, and clay soils. It also grows in soils from slightly acid to slightly alkaline. PFAF lists USDA zones 9–11 but says frost can harm it. A cold greenhouse may shelter plants through a mild winter. Sow seed under glass in spring. Seeds take about two weeks to sprout. Move young plants outdoors after the last expected frost. Take half-ripe cuttings in summer and keep them warm through winter.

People eat young leaf buds, young leaves, flowers, and roots. The leaves and flowers taste mild and feel slippery. People eat them raw or cook them with other foods. The roots are edible but have tough fibres and little flavour. These food uses carry a warning for those who are pregnant. Both food-plant sources report a possible link to causing abortion. Useful Tropical Plants links that report to juice from the leaves. The evidence does not show broad safety for people or pets.