Peganum harmala aka Syrian Rue

Peganum harmala is a perennial in the Nitrariaceae family. Common names include harmal and Syrian rose. Its native range spans the Mediterranean to Mongolia and India. It is not native to Britain or Ireland. Kew places it in the subtropical climate zone. In the wild, it grows on dry steppes and waste ground. It also grows in salty soils and heavily grazed places.

Plants reach about 2 feet (0.6 metres) tall. They spread to about 1.6 feet (0.5 metres) across. Each flower has both male and female organs. Seeds ripen in September. These seeds account for many of the plant's recorded uses. The supplied sources give no further detail on flower colour or leaf shape.

Grow harmal in an open site with full sun. It does not grow in shade. It suits sandy or loamy soil with very good drainage. Poor soil can support it, as can saline ground. Its soil range runs from mildly acid to mildly alkaline. It prefers dry ground but can also grow in moist soil. One source favours soil that drains well yet holds some moisture. Garden beds and sites beside south-facing walls are listed growing places. PFAF lists USDA zones 7–10. It reports survival near −4°F (−20°C) when the soil stays dry.

Seeds can be sown under glass in late spring. Move seedlings into separate pots once they are large enough. Keep young plants in a sunny greenhouse through their first winter. Plant them outside in late spring or early summer. Avoid excess water, above all while plants are dormant. Division in late spring offers another way to raise plants. PFAF flags the species as potentially weedy. That warning does not establish how invasive it may be locally.

The seeds have recorded uses as a spice and oil source. These uses do not mean they are safe to eat. Seeds contain alkaloids with narcotic and hallucinogenic effects. Excess intake can cause vomiting and hallucinations. Traditional medicine uses the fruit and seeds for several complaints. PFAF urges caution and guidance from a qualified practitioner. Seeds also yield a red dye used for carpets in western Asia. They serve as incense as well. These practical uses sit alongside the plant's clear safety concerns.