Crotalaria retusa, rattleweed, is a yellow-flowered weed of wasteland and field edges whose dry pods rattle when shaken. It contains monocrotaline and other pyrrolizidine alkaloids that damage the liver and lungs. It has poisoned livestock and people who ate contaminated grain, and it is not a food.
- Botanical name
- Crotalaria retusa L.
- Family
- Fabaceae
- Tamil
- Kilukiluppai
- Hindi
- Ghunghunan
- Parts used
- None as food
- Habit
- Rattle pod; sunn hemp is C. juncea
- Last updated
- 2026-10-25
How to recognise Rattleweed
It is an upright annual or short-lived perennial, about a metre tall, with simple, wedge-shaped leaves that are broadest near a notched tip. The name retusa means “notched”.
Flowers are bright yellow pea-flowers with reddish-purple veins, in long spikes.
The pods are inflated, smooth and black when ripe. The loose seeds rattle inside, which is where the name rattlepod comes from.
Sunn hemp, Crotalaria juncea, is grown as a fibre and green-manure crop and has narrow leaves.
Traditional use of Rattleweed
Village knowledge
Children shake the dry pods as rattles. The plant has appeared in folk lists, but its toxicity rules out internal use.
Indian village practice
Modern notes on Rattleweed
Monocrotaline is a well-known pyrrolizidine alkaloid used in laboratories to induce lung damage in animal studies. Grain contaminated with Crotalaria seeds has caused outbreaks of liver disease.
Farmers should keep it out of fodder and grain fields.
Rattleweed safety
Do not eat any part. Remove it from grazing land and keep its seeds out of harvested grain.
Ecology and sourcing
It is native to Africa, Asia and Australia and grows on disturbed ground, roadsides and coasts.
It fixes nitrogen and flowers for months, attracting bees and butterflies.
Some moths feed on Crotalaria as caterpillars and store its alkaloids to protect themselves from predators.
Related plants
Also in Fabaceae
Questions about Rattleweed
Is Rattleweed sunn hemp?
No. Sunn hemp is Crotalaria juncea, a fibre crop.
Why does Rattleweed rattle?
The seeds rattle loosely inside the dry pod.
Is Rattleweed poisonous?
Yes. Its alkaloids damage the liver.
How do I remove Rattleweed?
Pull the plants before the pods ripen, and never feed them to animals.
Sources
- Crotalaria retusa L. — Plants of the World Online, Kew (search) (accessed 2026)
- Wikidata item Q10917487 (Crotalaria retusa)
Educational page about a plant. It is not medical advice, not a diagnosis, and not an offer to sell. Traditional use is historical. If you need care, ask a licensed clinician. Questions: hello@meevamed.com.