落下した銀杏の雄花で歩道が薄黄色に：2025年4月24日（木）

【要旨】
2025年4月23日，京都市の堀川上立売付近にある「せせらぎ公園」では，銀杏並木の雄花が落下し，歩道や中央分離帯が淡い黄色に染まった。銀杏は雄株と雌株があり，秋に臭い実をつけるのは雌株であるため，街路樹には雄株が多く植えられている。雄花と雌花の見分け方には枝ぶりや樹形の観察が有効とされており，季節の移ろいとともに自然の細やかな違いを楽しむ視点が紹介されている。

【本文】
京都市の堀川上立売あたりの「せせらぎ公園」に林立する銀杏並木が芽吹いた葉で青々と生い茂り，この時季，雄の銀杏の木の下には，たくさんの雄花が落下して，中央分離帯付近から横断歩道のあたり，および公園の歩道が薄黄色に染まっている（上の写真と下の写真，2025年4月23日，筆者撮影）。

　銀杏は雄雌異株であり，雄と雌の木があり，雄株に雄花がつき，雌株に雌花がつく。ただし，一つの株で雄花と雌花をつける株もあるという。目の前にある銀杏の木が，はたして雄株なのか，雌株なのかを見分けるには「樹形や枝振りをみて， 典型的な雌株は幹から太い枝が水平に近い角度で出て二次の枝先が垂れ下がっていて全体的に枝がまばらであるのに対して，典型的な雄株は幹から太い枝が狭い角度で出ている」点を観察すればよいという。

　秋になると，銀杏（ギンナン）の実をつけるのは雌株のほうである。秋にギンナンの臭いにおいを減らすために，街路樹では雄株の銀杏の木をあえて多く植栽することも考慮しているということのようだ。

The sidewalk turned pale yellow with fallen male ginkgo flowers: Thursday, April 24, 2025

Summary
On April 23, 2025, at Seseragi Park near Horikawa Kamidachiuri in Kyoto, fallen male ginkgo flowers colored the sidewalks and median strips a soft yellow. Ginkgo trees have both male and female varieties, and since the female trees produce foul-smelling fruit in autumn, male trees are more commonly planted along streets. Observing branch structure and tree shape is considered helpful in distinguishing between male and female trees. The article highlights an appreciation for subtle seasonal changes and the quiet beauty of nature in everyday surroundings.

Main Text
The rows of ginkgo trees lining Seseragi Park, near Kamidachiuri Street on Horikawa-dori in Kyoto City, have grown lush with freshly sprouted green leaves. Around this time of year, numerous male ginkgo flowers fall to the ground beneath the male trees, turning the central median strip, the area near the pedestrian crossing, and the park’s walkways a pale yellow (as seen in the photos above and below, taken by the author on April 23, 2025).

Ginkgo trees are dioecious, meaning there are separate male and female trees—male trees produce male flowers, and female trees produce female flowers. However, it is said that some trees may bear both male and female flowers. To distinguish whether a ginkgo tree in front of you is male or female, one can observe its shape and branching pattern: a typical female tree has thick branches that grow almost horizontally from the trunk, with secondary branches drooping and an overall sparse appearance. In contrast, a typical male tree has thick branches that grow from the trunk at a narrow angle.

In autumn, it is the female ginkgo trees that bear fruit (ginkgo nuts). To reduce the unpleasant odor of the ginkgo nuts in the fall, it seems that urban planners often choose to plant more male ginkgo trees as street trees.