The secret of the beauty of Somei-yoshino cherry blossoms
If you visit Japan in April, you will see a magnificent view of sakura all over the streets, and most of these cherry blossoms are Somei-Yoshino. Somei-Yoshino has such lovely features because the beauty is “artificial”.
Somei-Yoshino is a hybrid cherry blossom, bred by planters in the Edo period (1603 -1868) based in Somei village, an area in northern central Tokyo today.
Sakura is categorised as part of the rose family, which has the property of self-incompatibility; the characteristic that prevents self-fertilisation. Somei-Yoshino is a single hybrid species. Therefore, it cannot make seeds on its own. We need to graft Somei-Yoshino to have another tree. Thus, all Somei-Yoshino trees have the exact same DNA: a clone.
Somei-Yoshino has the following characteristics that other sakura species do not have; leaves grow after all the flowers fall off, flowers are bigger than other species, and the petal colour is soft pink which is favoured by Japanese people.
Other sakura species blooms each by each, and sakura flowers bloom only for a week or two, so we cannot expect the view of all sakura are blooming at the same time except for Somei-yoshino.
Somei-Yoshino trees bloom at the same time because they are a clone. Since all Somei-Yoshino trees can be, in a sense, considered the same individual, all of them bloom at the same time once the temperature hits a particular degree, which makes for a glorious view.
Somei-Yoshino can crossbreed with other wild cherry species. However, descendants of Somei-Yoshino won’t have the beautiful features of their mother because they will have genes from different species.
Also, since Somei-Yoshino is a clone, it has a lot of problems. There is no genetic variation among Somei-Yoshino trees, so all of them are susceptible to some particular diseases.
Somei-Yoshino can cause genetic pollution as well. Since the Japanese have planted only Somei-Yoshino all over Japan, wild sakura trees might pollinate with Somei-Yoshino a lot, and then, the original “pure lineage” species cannot be sustained.
Personally, I am not worried about the latter issue because, genetically or evolutionary speaking, there are no “pure” or “hybrid” species; all the species, including Homo-Sapience, are mixed and crossbred from the beginning of the birth of life.
Humans picked a few dog species as their favourite “dog breeds”, and always pure strain dogs cannot escape the issue against genetically related diseases. In the case of Bulldogs, over 80% of them are delivered by Caesarean section because humans favoured their big heads and tiny limbs and bred the individual having these features. It is against natural selection and unhealthy for dogs, although they will never be extinct as long as humans adore them. Chickens and cows also thrive by “human selection”.
Nevertheless, it is sad that there is not much variety among sakura we see anymore because of this artificial reason. Apart from Somei-Yoshino, there are beautiful sakura trees, indeed. They do not look like the “Japanese sakura”, but I found beauty in them.
Japanese people wrote a lot of poems about the beauty of sakura from ancient time, but since Somei-Yoshino did not exist until around the 18th century, thus, they were admiring the other sakura species, which is the so-called Yamazakura.
We do not see these species so much in the park or street, but when I go hiking, sometimes I do find Yamazakura, and it makes me happy.