The Secret Behind the Beauty of Somei-Yoshino Cherry Blossoms
Should you visit Japan in April, you’ll be greeted by a breathtaking display of sakura lining the streets. The majority of these cherry blossoms are called Somei-Yoshino. The beauty of Somei-Yoshino is, in a sense, “artificial”.
Somei-Yoshino is a hybrid cherry blossom, cultivated by planters during the Edo period (1603 -1868) in what was then the Somei village, now a part of central Tokyo.
Sakura belongs to the rose family, which possesses the trait of self-incompatibility, preventing self-fertilisation. Somei-Yoshino is a unique hybrid species and cannot produce seeds independently. To propagate, Somei-Yoshino must be grafted, ensuring that all Somei-Yoshino trees possess identical DNA: they are clones.
Distinctive features of Somei-Yoshino, not found in other sakura species, include leaves that appear only after all the flowers have fallen, larger flowers, and soft pink petals, which are particularly admired by the Japanese.
Other sakura species bloom sporadically, and sakura flowers typically last just a week or two. Hence, the simultaneous blooming seen with Somei-Yoshino is exceptional.
The synchronised blooming of Somei-Yoshino trees is due to their clonal nature. As they are genetically identical, they all bloom concurrently when the temperature reaches a specific threshold, creating a spectacular sight.
Although Somei-Yoshino can crossbreed with other wild cherry species, their offspring won’t retain the exquisite features of the parent, due to the introduction of genes from different species. Also, being clones, Somei-Yoshino trees face challenges. The lack of genetic variation makes them vulnerable to certain diseases.
Additionally, some says Somei-Yoshino can contribute to genetic pollution. With Japan predominantly planting Somei-Yoshino, wild sakura trees frequently cross-pollinate with them. This threatens the continuation of the original, distinct species.
However, personally I’m not overly concerned. Genetically and evolutionarily speaking, no species is truly “pure” or “hybrid”. Every species has evolved through mixing and crossbreeding since life’s inception.
Humans have selected specific dog breeds as favourites, and purebred dogs often face genetic health issues. For instance, over 80% of Bulldogs are born via Caesarean section due to the human preference for their large heads and small limbs. This selective breeding goes against natural selection and is detrimental to the dogs. Yet, as long as humans cherish them, they won’t face extinction. Similarly, chickens and cows flourish due to “human selection”.
Still, it’s disheartening to see limited sakura variety today for such artificial reasons. Beyond Somei-Yoshino, there are indeed other beautiful sakura trees. They might not fit the typical “Japanese sakura” image, but I find them captivating.
Historically, the Japanese have penned countless poems celebrating sakura’s beauty. Since Somei-Yoshino didn’t emerge until around the 18th century, they were praising other sakura species, notably Yamazakura.
These species aren’t commonly found in parks or streets. However, during my hikes, I occasionally stumble upon Yamazakura, and their sight always brings me joy.