Hello! It is I, your Osteospermum, speaking. You have noticed my flowers closing, and I appreciate your concern. Please, do not worry; this is not a sign of distress but rather a fundamental part of my being. My opening and closing are governed by an internal rhythm synchronized with the sun, a phenomenon known as nyctinasty. As the sun rises, its light and warmth signal my petals to unfurl, stretching wide to welcome the day's primary pollinators—bees. This maximizes my exposure to these vital partners. As evening approaches and light levels diminish, along with a drop in temperature, my petals receive the signal to close. This conserves my energy and protects my precious reproductive parts, the pollen and nectar, from the chill and moisture of the night.
While my daily solar cycle is predictable, you may also see me close my flowers during the day. This, too, is a clever survival tactic. My petals are highly sensitive to light intensity. On an overcast, cloudy, or stormy day, the lack of intense sunlight tricks me into thinking it is evening. By closing, I shield my pollen from being washed away by rain or diluted, ensuring it remains viable and potent for when a suitable pollinator arrives. Similarly, if a sudden shadow falls over me for an extended period, I may begin to close. It is not a sign of unhappiness with my location, but simply an automated response to the environmental cues I am receiving.
From a broader perspective, this opening and closing is a brilliant evolutionary strategy for resource management. Producing flowers and nectar requires a tremendous amount of my energy. It is a costly investment. By closing at night or during unfavorable weather, I am practicing conservation. I am not wasting my nectar on nocturnal insects that are not my target pollinators, like moths. Furthermore, closing up protects my delicate pollen grains from being ruined by dew or frost. This ensures that when I open again under favorable conditions, my offerings are fresh, potent, and attractive to the bees that effectively ensure the continuation of my species through pollination.
It is also worth noting that some of my cultivated cousins have been bred for specific traits, which can sometimes affect this natural behavior. Certain newer hybrids may not close as tightly or as predictably as my wild ancestors. Furthermore, the age of the individual flower plays a role. A brand new, freshly opened bloom will be far more vigorous in its response to light than an older flower that has been open for several days and is nearing the end of its life cycle. An older flower may remain partially closed or not react as dramatically to dim light.
