What plant requires 12 or more hours of darkness?

The plant that requires 12 or more hours of darkness is typically known as a "short-day" plant. These plants, like chrysanthemums and poinsettias, initiate flowering in response to longer nights and shorter days, usually requiring a minimum of 12 hours of uninterrupted darkness. This triggers the production of flowering hormones, allowing them to bloom during the fall and winter months. Proper light and dark cycles are crucial for their growth and flowering success.