They are all herbaceous plants native to Eurasia and northern Africa, with several widely naturalised across much of the temperate world.

The genus includes both annual and perennial species; they spread by both seeds and stems rooting as they grow along the ground.

They have square stems[3] and coarsely textured pairs of leaves, often with striking patterns or variegation.

[8][9] The name comes from the Greek laimos, which means "gullet", a reference to the gaping throat-like appearance of the corolla.

and northern Africa, but several have become very successful weeds of crop fields and are now widely naturalised across much of the temperate world.