A “Cylinder of Living Cells”
In August 1945, Hiroshima’s ginkgo trees were in full leaf. When the bomb hit, the heat immediately burned those leaves into nonexistence. The branches were instantaneously stripped away, leaving the outer bark completely scorched.
But, as Crane explains, the tree was still alive on the inside. Somewhere underneath all of the destruction, a tiny cylinder of “living cells” had to have survived. Fortunately for the ginkgo tree, the extreme organization of its cell tissues created a compartment that was immune to destruction. On its very outside is the bark, a shell of hard, dead cells. Inside is the softer phloem, which carries sugars that feed the other cells. Then comes the xylem, a wood-producing layer of the tree. Closest to the core is the cambium, which Crane calls a “cylinder of living cells.”
The A-bomb almost certainly destroyed the dead outer layers, but Crane hypothesizes that the ginkgo bark was just strong enough to protect the life within.
“So now you’ve got a bare tree with no leaves, but come spring, there’s still enough energy there where buds can be developed and new leaves can start to form,” he says.
“It’s those living tissues that would supply the nutrients coming out from the roots that would differentiate into leaves the next season.”