The blossoms of plum trees, especially of the genus Prunus mume. The petals are white and red, and bloom in early spring.
The aesthetic of the plum blossom has always been of major importance across East Asia, and while viewing them was initially a popular practice in Japan beginning in the Nara period, it was overshadowed by the popularity of cherry blossoms during the Heian period. This preference was only reinforced by subsequent generations of intellectuals, who in effect argued the sakura to be more quintessentially Japanese.
Today, however, some older Japanese who find sakura hanami too crowded and noisy take to plum blossom viewing (or umemi) instead, enjoying the peace of its relative obscurity.
Distinguished from cherry blossoms in that cherry petals have slits at the ends of the petals. Plum petal ends on the other hand are round (see reference).