KnowraIsatis tinctoriaLinked fromLinked fromThe 4 pages that link to Isatis tinctoria, each with the reason it gives.All 4Broader topic 1Compared with 3Indigo dyeCompared with: It provided a regional source of indigo before imported tropical dye became dominant.IndigoCompared with: It was a major European blue dye before imported indigo became dominant.IndigoferaCompared with: It supplied a similar dye in regions where Indigofera was less accessible.