Some flower books relate that Weld is alternatively called Dyers Greenwood, but most books report that Dyers Greenwood is Dyers Broom or Genista Tinctoria. Weld was indeed used commercially to yield a lemon yellow dye, just as Dyers Greenwood (Genista Tinctoria) was used to yield a green dye. and this is perhaps where the confusion has arisen. Weld grows at great speed to 6 feet tall, hence the synonym Dyers Rocket. A great many different flowers were used as dyes at one time.

Easily confused with : Wild Mignonette, but Weld is much taller, and also much more slender in relation to its height.

This plant was once grown commercially for the deep yellow dye luteolin, a flavonoid, which can be extracted, mostly from the seeds. This dye is a very stable pigment used for dying both wool and silk since ancient times. Luteolin in the human body acts as an anti-oxidant and is a moderator of the human immune system. Luteolin is also called Luteoline, Digitoflavone and Flacitran. Weld also contains Apigenin another flavonoid and natural yellow dye.

Weld is heliotropic and follows the Sun around the horizon during the day, even when the Sun is behind clouds!