Woad (Isatis tinctoria)
- Also called dyer’s woad or glastum
- Perennial herb in the cabbage family. A summer-flowering plant
- Woad was formerly grown as a source of blue dye.
- The dried leaves, when wetted and fermented, produce the blue crystalline compound indigotin.
- Woad reaches about 90 cm in height and has a long taproot. The hairy stem leaves have arrow-shaped bases, and the long basal leaves are downy and lance shaped.
- The plant bears small four-petaled yellow flowers and produces clusters of dangling winged single-seeded fruits.
- Certified Organic IE-ORG-02
- Seed supplied by Irish Seed Savers.
- The leaves of this plant are the source of a blue dye, often used instead of indigo.
- Leaves are collected from flowering stems, dried in the sun, ground into paste and left to ferment. The fermented leaves are then formed into cakes, mixed with water and fermented again. The colour is drawn out by infusing the woad with lime water.
- As well as being used for clothing, woad was once used by Celtic warriors to stain their bodies during battle. Some historians think the word Britain came from this custom of war-painting, as the old Celtic for paint was Brith and Brithon meant stained man.