Plantwatch: the bamboo that flowers once every 120 years

Bamboos can take years or even decades to flower, but the hachiku bamboo pushes this habit to the extreme – it flowers once every 120 years, synchronised across masses of plants, and dies shortly afterwards.

The last time the bamboo Phyllostachys nigra variety henonis flowered was in 1908, so the next event was expected in 2028 with great anticipation. But in 2020 botanists in Japan noticed that a few specimens began flowering early. However, they were shocked to discover that after flowering the bamboos failed to produce any viable seeds, or grow new shoots, and entire forests of bamboo collapsed and died in an act of mass self-destruction.

After the last mass flowering event in 1908 the bamboo colonies also collapsed, but years later they somehow re-established themselves throughout Japan. How the bamboo managed to regenerate remained a mystery.

One theory is that the bamboo regrows underground before sprouting new woody stems above ground, although this may take years and result in a huge loss of colonies, leading to wide open spaces and environmental problems such as soil erosion, loss of food for wildlife and lack of bamboo materials for local industries.