Chrozophora tinctoria aka Dyer's Litmus

Chrozophora tinctoria is part of the spurge family, Euphorbiaceae. People also call it tournesol and bezetta rubra. Kew gives its native range as the Mediterranean to Central Asia and northwestern India. Plants For A Future lists it in southern Europe and North Africa. That list includes the Middle East and parts of Asia, too. The RHS says it is not native to Britain or Ireland. Kew links the plant to a subtropical climate.

The sources do not agree on how long it lives. Kew calls it an annual: its life ends within one year. Plants For A Future calls it a perennial, a plant that lives for years. Yet that source says it flowers late, then dies. These accounts leave its lifespan unclear. The evidence gives no height or spread for a full-grown plant. It gives no details of leaves, stems, or the plant's shape. These gaps make its garden form hard to describe.

Plants For A Future places it in dry sites near coasts. In gardens, it lists full sun and part shade. It says the plant prefers moist soil, though its wild sites are dry. Its soil range includes sand, loam, and clay. The source lists slightly acid soil, neutral soil, and slightly alkaline soil. It names beds used to grow plants as a garden setting. The evidence gives no hardiness rating or clear limit for frost. It gives no bloom season or advice on pests and disease.

The clearest use is to make dyes, rather than food. Plants For A Future reports red and blue dyes from the plant. These come from its flowers, fruit, and sap. It calls the dyes edible but gives food use a low score. This does not show that whole flowers or fruits are safe foods. The evidence gives no way to prepare them or amount to serve. It gives no feeding advice, either. It lacks details of flower and fruit shape. Its accounts of the plant's sex organs also clash. Plants For A Future lists no known uses as medicine or known hazards. No known hazards does not mean it is safe for people or pets. The source says it has no scope to become a weed. Yet it gives no review by region.