Second year rosettes vary from 10 cm in diameter to nearly a 1 m and bolt to produce one to several flowering stems with varying amount of branching. Production per plant varies from 7000 in an Australian grazed pasture to 2,800 in an adjacent ungrazed field. In Holland, seed production on sand dunes varies with July rainfall from 250 to 2,800 per plant.
Seed is the only means of survival and the plant dies after flowering to leave a woody stem.
Thus, it takes about 200 seeds to produce one flowering plant. Seed on the surface has no dormancy and germinates, regardless of light, as temperature and moisture permit so many seedlings are under competing vegetation. However, dormancy is acquired in about half the over wintered seed that has imbibed in the dark. This needs light for germination 5 . Dormancy can occur under dense, damp vegetation, but burial is more effective, as the seed must remain moist to retain viability.