Last week, FiveThirtyEight and ESPN Films published the first in a series of short documentaries called The Collectors, profiles of people who use data in innovative ways. “Cartographers of the Edible World” introduced Ethan Welty and Caleb Phillips, who built an open-source, user-generated website that catalogs the location of edible plants all over the world. When the two men met, Phillips was interested in technology for social organizing. Welty was using publicly available data to map arable land. They both had maps for personal use that helped them forage food from city parks and public spaces in Boulder, Colorado, where they live.

Their website, Falling Fruit, has more than 786,000 data points, each of which represents a location containing one or more plants. What’s remarkable about the site is that 98 percent of the data points currently come from municipal tree inventories. When Welty was calculating the arable land in Boulder to determine how many people could be fed through urban agriculture, he used these tree inventories to subtract where trees are located, since planting in an area shaded by a tree is fairly useless. But then he realized a lot of those trees had edible components.