Some open only at night. In others, the flowers open for only a day or less. Then they wither and fall off. This short blooming period keeps water from evaporating from the big, soft petals. Life cycle of the cactus.
All cactuses reproduce sexually.
They bear flowers with male and female parts. The male part produces a yellow powder, called pollen. For a cactus to reproduce, its pollen must fertilize an egg cell in the female part of the plant. Insects, birds, or bats are attracted to the bright colors or the scent of the flowers. As they feed, these creatures carry pollen from one part of the plant to the other.