Four O'Clocks

These old-fashioned garden flowers are called four o'clocks. They are so named because their flowers open in the late afternoon between around four and eight o'clock. The flowers stay open all night and close the following morning, although sometimes remaining open on cloudy days. Click to enlarge.

 

I had heard that their scent was delicious so I sniffed a few recently and I can attest that they have a lovely, sweet, orangey aroma.

But why do they bloom at night? And why produce a scent anyway?

Because their pollinators are mainly moths who are attracted by scents and are active at night. It all seems perfectly logical now, right?