Vaillant's Pistachio

This pistachio helped prove that plants have sexes. In the early 1700s Sébastien Vaillant, a botanist at the royal garden that became the Jardin des Plantes, had a pistachio that flowered every year and never set fruit. The story told about it is that he took pollen from this one and shook it over a second pistachio, which then fruited, and in 1717 he set out in a public lecture that flowers have male and female parts. The tree he worked with is still alive, in a corner of the Jardin alpin. Its date depends on who you read. The description on its best-known photograph says it was planted in 1702; the Muséum's own head of botanical gardens has dated its sowing to 1704. Either way it is about 320 years old, and the oldest pistachio we know of in Paris. A reader on r/paris sent us here calling it a living witness of the history of science, which is exactly what it is. It does not look like much at first: a tree of modest size, with leathery leaves in threes and fives. The Jardin alpin is the sunken rock garden of the Jardin des Plantes, free to enter; the pin is where a photographer stood beside the tree, so look for the pistachio leaves there.