Populus nigra L
In ancient times the black poplar was associated with the kingdom of the dead, the entrance of which was delimited by these plants. In Greek mythology it represented the tree of Persephone, goddess of the dead met by Ulysses during his journey into the Underworld.
In one of the Greek myths it is said that one day Phaeton, son of the Sun, finding his father's wagon unattended, took it to drive it in the sky. But, approaching the Earth, it caused many fires in the woods, while, going too far, it caused cold and frost. Jupiter's anger was such that, to punish him, he threw him against lightning. Phaeton, struck, fell into the river and his sisters, the Eliadi, wept for a long time. The Jupiter, moved with compassion, transformed them into Poplars, leaving them lined up along the bank of the Eridan River. In spring, droplets of resin still fall from the buds of the Poplars, symbolizing the tears of the Eliadi.
The diffusion of the Italic variety of black poplar, introduced in France from 1745, was do to Napoleon. He had it planted almost everywhere along the French roads travelled by his armies, to avoid making them march in full sun in the summer and to facilitate orientation during winter.
Curiosity: the name populus (people) probably derives from the Roman tradition of planting it in public places, making this plant very popular. Piazza del Popolo, in Rome, owes its name to the ancient presence of poplar trees.
Bibliography:
https://www.waldwissen.net/wald/baeume_waldpflanzen/laub/wsl_schwarzpappel/index_IT https://www.floraitaliae.actaplantarum.org/viewtopic.php?t=4172