Short answers, pulled from the story.
Marco Polo was the first European to document the complex preparation of indigo dye after returning from Asia in the 13th century. He brought tales of a plant that could turn water into the deepest blue imaginable.
The transformation begins when the glycoside indican within the leaves meets water and air during fermentation. This process converts indican into indigotin, the actual blue pigment, which is then precipitated using a strong base like lye.
The plant became a central pillar of colonial life in South Carolina during the 18th century. A scholarly study by Andrea Feeser details how the popularity of this dye bound together local and transatlantic communities during this period.
Indigofera tinctoria grows wild from tropical West Africa across to the Indian subcontinent and mainland Southeast Asia. The shrub thrives as an annual, biennial, or perennial depending on the local weather conditions.
Indigofera tinctoria is valuable for sustainable farming because it improves soil through nitrogen-fixing properties found in other legume crops. Farmers rotate the plant into fields to restore depleted earth and ensure land remains fertile enough to support other crops.
The plant contains a family of toxic compounds known as rotenoids, including deguelin, dehydrodeguelin, and rotenone. These compounds serve as natural pesticides to protect the shrub from insects.