COOLIDGE, Ariz. (AP) — It literally stinks that visitors to Casa Grande Ruins National Monument in south-central Arizona might not be able to use the attraction’s picnic area until May.

Monument officials announced Wednesday that the picnic area will be closed from March 28 through April 30 due to the density of an invasive and noxious winter weed called stinknet that can grow more than 2 feet (0.6 meters) tall.

The weed has a turpentine-like odor and can cause serious breathing problems as well as severe skin rashes.

Stinknet has bright yellow blossoms on narrow green stems. The blossoms are round and similar to the shape of golf balls, right down to the dimpled pattern.

Arizona Native Plant Society officials said stinknet explosively spread in Maricopa County during the wet fall and winter seasons of 2016, 2018 and 2019.

That led to heavy infestations on the north fringes of Phoenix and Scottsdale along with rapid movement southward to Casa Grande.

Monument officials are asking visitors not to walk near — or step on — the flowering weed to avoid spreading it.

They said the Casa Grande Ruins team is working on a solution that will get the picnic area reopened as soon as possible, but they said it may take until May 1.

The monument, located in Coolidge about 20 miles (32 kilometers) northeast of Casa Grande, preserves a group of structures built by the Hohokam tribe more than 700 years ago.