Ocotillo (Fouquieria splendens), at the Millville Townsite, Cochise County, Arizona.

Ocotillo is a drought deciduous plant, meaning it will lose its leaves any time of year if there are prolonged dry spells, to conserve water in its woody branches. But it also responds to the changes in day length and cooling temperatures in fall, and can put on a colorful show before losing its leaves.