Hortus Botanicus is 1.2 hectares with roughly four thousand species packed into it, and two of the plants that passed through changed what large parts of the world now farm. One was coffee: a plant raised here went to Louis XIV in 1714, and by the usual account the coffee of the Americas descends from cuttings taken from it. The other was the oil palm, and most of the Southeast Asian crop descends from seedlings planted at Bogor in Java in 1848, two of them from Amsterdam.
It began in 1638 as the Hortus Medicus, a working supply of raw material: Amsterdam's doctors and apothecaries needed the plants their medicines were made of, so the city grew them. Within fifty years the job had changed, because ships were coming in with species no one in Europe had seen. The garden moved to this ground in the Plantage in 1682, and Jan Commelin set about describing and publishing what arrived. A plant could be landed, potted, drawn, named and sent on again. Walk the beds now and you are crossing a garden that was planted to stock medicine chests and ended up holding plants from the far side of the world.