New Yorkers document city’s plants, catalogue 26,000 sightings

Susan Hewitt found a special prize recently while wandering the streets of New York.

The 70-year-old spotted a mysterious patch of bright green leaves with tiny white flowers in a raised flower bed. It turned out to be tropical Mexican clover, a weed common in South America and Florida’s orange groves, but never recorded before in the state.

“I get a tremendous kick out of identifying things,” she said. “There’s nothing more exciting.”

Hewitt volunteers for an ambitious project to photograph all the wild plants that dwell in New York City. On Friday, the organizers announced that citizen scientists had catalogued more than 26,000 sightings, and documented new populations of invasive species and native weeds that seem to be disappearing, like the green comet milkweed.

Started last year by scientists at the New York Botanical Garden, the effort makes up for the lack of manpower to survey the entire city.

“There are just not enough of us,” said Regina Alvarez, a professor at Dominican College in New York who isn’t part of the effort. “What we’re studying requires a lot of data and it’s really hard for the number of scientists that are out there to do all that work.”

The project so far has attracted 730 volunteers armed with smartphones who’ve hit the streets for the quest, called New York City EcoFlora.

Hewitt, a self-described naturalist who grew up near the English village where Charles Darwin lived, made her discovery last month in front of a massive apartment building in Manhattan’s Upper East Side. She fires up her iPhone X every time she spots something new or interesting. A fragile tree seedling sticking out of a manhole cover? Click. A white petunia hidden among weeds? Click.

Botanist Brian Boom, who heads the project, said the scientific community wasn’t really thinking about the need to engage with regular folks when he was a graduate student in the early 1980s.