The Ginkgo of the Sperm Discovery
You need a ticket to see this treePaid entry, 500 yen (University of Tokyo botanical garden)
How do I find it? You can recognise it by the stone marker at its foot, placed in 1956 for the sixtieth anniversary of the discovery made under it. It stands in the Koishikawa Botanical Garden, a female tree that carpets the ground with nuts each autumn.
In 1896, a botanist working under this tree changed what science understood about how plants reproduce. Hirase Sakugoro, an artist-turned-researcher with no university degree, spent years examining ginkgo ovules from this specimen at what was then Tokyo Imperial University's botanical garden. He discovered that ginkgo trees produce swimming sperm cells, motile and flagellated like something out of animal biology, a reproductive method no other seed plant on Earth was known to use. It overturned assumptions about the evolutionary line between ferns and flowering plants and made the ginkgo, already ancient as a genus, into a living fossil in the most literal sense: a plant still reproducing the way its ancestors did 200 million years ago. The discovery is commemorated with a stone marker at the tree's base, placed for its sixtieth anniversary in 1956. The tree itself, one of the female specimens whose ovules made the discovery possible, is estimated by ring count at around 300 years old, and it still drops a heavy carpet of ginkgo nuts every autumn, oblivious to its own scientific importance.
- Species
- Ginkgo (Ginkgo biloba)
- Location
- Koishikawa Botanical Garden, 3-7-1 Hakusan, Bunkyo-ku, Tokyo 112-0001 (Hakusan, Bunkyo)
- Getting there
- 10 min walk from Hakusan Station (Toei Mita line)
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Sources
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