The moonflower, Ipomoea alba, is a kigo for late spring / early summer. Its large, fragrant, round blossoms are revealed after dusk in a dramatically rapid fashion, often seeming to almost spring open.
Related to the morning glory, it is native to tropical and sub-tropical regions of North and South America. The large 4-5 inch flowers range in color from white to pink, and are often cultivated as a garden ornamental. In regions like Florida, it can become an invasive twining pest, choking out other plants.
The pre-Colombian Mesoamericans civilizations used the high sulfur content of the moonflower plant to vulcanize latex from the Catilla elastica tree into rubber balls used in arena sports.