Flowers and Fruits Each flower head contains 250 to 1,500 flowers that are packed into dense, cone-shaped heads. Each flower blooms for only one day. The flower itself has white petals united into a tube with four purple lobes. Four stiff, upwardly curving bracts are located underneath the flower head. Common teasel flowers April through August in California, and July through September in the Midwest and Northeast. The fruit is a hairy achene, or a dry fruit with a single seed and thin walls that does not open at maturity, like a sunflower “seed”.