My grandmother doesn’t talk about the bomb. Whenever I ask, she claims she doesn’t know what happened to her family, though I suspect she simply doesn’t want to think about it.

She was 20 years old and living in Honolulu on the morning of Aug. 6, 1945, when the United States dropped a nuclear weapon on Hiroshima. It detonated directly over the neighborhood where her family — including her grandmother, aunts, uncles and cousins — lived. The bomb destroyed the city and killed over 100,000 people. She was told that only one uncle survived.

Scientists estimate that during the explosion the ground temperature ranged from 3,000 to 4,000 degrees Celsius — hot enough to transform a human body into a fine black dust. When I think of that day, I imagine our family gathering around a table for breakfast and ending up in the wind.

I have never been to Hiroshima, but for a long time I have felt a strong desire to connect physically with this part of my family’s history. I have been searching for things that survived — an heirloom, a letter, a bracelet.

Unexpectedly, the objects that have offered me the most meaningful connection to Hiroshima are not objects at all but living, breathing things: trees.

Ginkgo trees, to be precise.

The ginkgo — a species native to China with fan-shaped leaves that turn a vibrant gold in the fall — is one of the oldest and most resilient trees on earth. These trees survived the asteroid that killed the dinosaurs and were some of the only living things to survive the bomb, which they managed to do because their roots grow deep enough in the soil that they were protected from the incinerating heat.

In Japanese, human survivors of the atom bomb are called hibakusha. These surviving trees have a name as well: hibakujumoku.

Some of the original trees are still alive today, and — like many human survivors — they and their descendants are scattered across the globe.

Hideko Tamura Snider, a hibakusha from Hiroshima, was 10 years old when the bomb killed her mother, her best friend and many of her relatives. In 2003 she moved to Oregon, and in 2017 she partnered with Green Legacy Hiroshima — an organization that cares for the hibakujumoku — to bring seeds of the surviving ginkgo trees to the United States. Ms. Snider planted the seeds, 51 in total, and called them “Hiroshima peace trees.”

In a 2019 interview with NBC’s Klamath Falls station, Ms. Snider reflected: “I can’t grow my mother. I can’t grow my cousin. But the tree, I could.”

Over the past few months, I have been visiting the peace trees around Oregon. I give them water. I take photos. I feel their notched leaves. I thank them for being here and let them know I am here, too.

The bomb’s explosion was so bright it turned concrete surfaces in Hiroshima into photographic negatives. In one instance, a human-shaped shadow is fixed onto the steps in front of a bank. Everything but the outline of the person is bleached milky white from the blast.

I thought about the bomb’s relationship to light, shadow and photography as a whole as I photographed these trees, often including my own shadow in the frames.

Every shadow tells the story of a body: a body resting, a body dancing, a body watering houseplants, a nervous body, an aching body, a body hugging another body, a classroom of bodies, a market of bodies buying vegetables and oil and toilet paper and shoes, a street crowded with bodies on their way home, a neighborhood of bodies living so closely that they all know one another too well — who is always frying something, who doesn’t come home, who stays up with a light on all night.

A city full of bodies.

My grandmother, who is 97, was planning to return to Hiroshima this fall, but now it looks like she may not be able to. I would have loved to go there with her, but if she can’t make the trip I will go alone.

I will visit the place where our family once lived, and I’ll visit the hibakujumoku, the mothers and grandmothers of the saplings I have come to know so well. I will feel their leaves and tell them that we made it, that we survived.

Will Matsuda is a photographer and writer based in Portland, Oregon.