Plumbago zeylanica aka Doctorbush

Plumbago zeylanica is also known as leadwort. It belongs to the Plumbaginaceae family. Kew says it is native across the tropics and subtropics. Useful Tropical Plants gives a smaller range: India and Malaysia. That source also says it now grows wild far beyond that range. This spread covers much of Africa and southeast Asia. The plant grows in tropical lands with a dry season.

This plant keeps its leaves and lives for years. It can form a shrub with stems that scramble. Some stems turn woody in part and last over time. Its loose stems grow about 3–7 feet [1–2 metres] long. They may spread on the ground or climb. These lengths refer to stems, not the plant's height when upright. Gardeners grow leadwort for its long groups of white flowers. It can bloom in any month of the year. Insects carry pollen between the flowers.

Leadwort grows best in full sun but accepts some shade. It likes soil that is a little acidic. In the wild, it often grows on open, disturbed ground. It grows in grasslands and at the edges of forests. It also grows in fields no longer in use. Records place it up to 3,280 feet [1,000 metres] above sea level. In Hawaii, it grows in dry scrub and woods. It also grows on sand dunes and other disturbed ground. These records show where it lives in the wild. They do not measure how much water it needs in gardens.

Growers can start new plants from seeds or cuttings. Seeds take about three to four weeks at 21°C to sprout. Fresh seed sprouts better than seed kept in storage. In one report, far fewer seeds sprouted after three months. Stem cuttings can grow roots in about one month. They need good new stem growth before moving to larger pots. Growers can also start plants from root cuttings.

The supplied account records no food use for leadwort. It is poisonous when swallowed, and large doses can kill. Paste made from the plant can harm skin and cause blisters. In Africa and Asia, people use it in traditional medicine. They treat skin problems and worms in the gut with it. This does not mean it is safe for home treatment. The root has also served as a dark dye for tattoos. This use depends on skin damage and can cause blisters. The plant contains plumbagin, which can cause strong irritation. Studies have looked at its effects on living things. Reports say it can keep insects from feeding. It can also disrupt moulting, when insects shed their outer skin. These findings do not prove it is safe to use as a garden pesticide.