Let's color the Cactus flower beautifully! Cactus plants rarely flower, but each flower of the plant is vibrant and soft, different from the rough stem. The flowers of the cactus are mostly bisexual flowers, depending on the species that bloom at different times. Cactus flowers have 5–50 sepals and 50–1500 stamens. The petals are uniformly and concentrically distributed and are about 5–30 cm long with many vibrant colors. The shape of the flower varies from funnel to bell to flat round.