The genus includes herbaceous annual, biennial and perennial species 40–130 cm tall. The leaves form a basal rosette at ground level, and then spirally arranged up the stem; they can be entire, toothed or pinnate, and range from 1–15 cm long.
The flowers are produced in a slender spike, each flower small (4–6 mm diameter), white, yellow, orange, or green, with four to six petals. The fruit is a small dry capsule containing several seeds.
Propagation is by seed, which is surface-sown directly into the garden or grass verge. The plant does not take well to transplanting and should not be moved after sowing
This plant is useful.