Japanese Morning Glory Flowers
Japanese Morning Glory flowers come in blue and purple colors. The reason to their name is because they are flowers that bloom in the morning and wilt in the afternoon, making their flower akin to a "beauty's face in the morning"... they have a strong image of summer in Japan and are also often used in haiku poetry to describe the coming of autumn.
Since these flowers have a short blooming phase, it's often described as a "transient love" and are used in heart-wrenching tales.
Here are some morning glories that mark the end of summer.