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Why Do Some Cacti Flower Only at Night—and Release Strong Fragrance After Sunset?
为什么一些仙人掌只在夜间开花，并在日落后释放浓烈香气？
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Nocturnal cacti like the night-blooming cereus open their large white flowers after dusk.
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They rely on moths and bats—not bees or birds—for pollination during darkness.
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Strong floral scent attracts these pollinators from hundreds of meters away in desert air.
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The fragrance chemicals include benzenoids and terpenes that evaporate best in cooler, humid night air.
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Flowers close before sunrise to conserve water and avoid daytime heat stress.
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Their petals reflect moonlight efficiently thanks to microscopic surface structures.
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Some species bloom just once per year, often synchronized by lunar cycles and rainfall.
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Scientists track flowering timing to assess climate change impacts on desert ecosystems.
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Genetic studies show rapid evolution of scent genes in response to local pollinator decline.
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This precise timing proves plant behavior is shaped by co-evolution—not mere chance.