Yellow Flag Iris
Yellow Flag Iris
Water & Wetland Plant
Britain's native wild iris of pond and river edges — tall, bright yellow flowers above sword-shaped leaves, and poisonous enough that grazing animals leave it alone.
💡 Fun Facts
- This is Britain's only wild iris with bright yellow flowers, standing tall at the edge of ponds and rivers in early summer.
- It has flat, sword-shaped leaves that point straight up out of the water.
- Almost nothing eats it — the whole plant is poisonous, so grazing animals like cattle and ponies leave it well alone.
📅 Through the Year
- Flowering:May to July
Name Story
Iris pseudacorus
means “the rainbow that’s a false sweet-flag”
What does its name mean?
- Iris — rainbowGreek iris ‘rainbow’, also the goddess of the rainbow
- pseudacorus — false sweet-flagGreek pseudes ‘false’ + Acorus, the sweet-flag plant
Iris was the Greek goddess of the rainbow, and iris flowers bloom in rainbow colours. The ‘false’ in its name is a gentle warning: out of flower, its tall sword-like leaves look so like the sweet-flag plant that people easily muddle the two.