The saguaro cactus is perhaps the most iconic symbol of our state. You can find it everywhere from coffee cups to murals to tattoos. People love saguaros but we know surprisingly little about them.

The Desert Botanical Gardens in Phoenix and other researchers are trying to fix that. The first step is to count as many of the saguaros growing in the Valley as possible.

"Naively, we call this the Saguaro Census because we thought we were going to be capable of counting every single saguaro in the city. We clearly overestimated our capabilities because the Phoenix Valley is huge," Tania Hernandez says. She works as a research scientist at the Desert Botanical Gardens.

For help with this task, the Gardens are turning to the public for help.

In this episode of The Lab, in conjunction with Valley 101, we're exploring two questions: why does the saguaro cactus only grow in the Sonoran Desert? And how many are there?

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